Ballona Wetlands SEA (Subareas 4a – 4b)

Proposed:
Extend the SEA downstream to incorporate Del Rey Lagoon and Toes Beach Dune, and upstream to include the Bluff Creek riparian corridor. These additions expand the SEA to capture connected coastal wetland, dune, and riparian habitats that function as an integrated ecological system within the lower Ballona Creek watershed.

Primary Ecological Justifications:

• Criterion A: Least Bell’s vireo nests within the Bluff Creek riparian corridor.
• Criterion B/C: Least bittern and northern yellow warbler, both California Species of Special Concern, over-summer and likely nest within the Bluff Creek corridor.
• Criterion D: Del Rey Lagoon functions as a significant congregation and foraging area for waterbirds; over 218 avian species have been documented, including egrets and herons that nest nearby in Marina del Rey, as well as wintering and migratory ducks, shorebirds, gulls, and other waterbirds.
• Criterion E: Coastal riparian woodlands, lagoons, and dune systems are rare and severely depleted habitat types in Los Angeles County.
• Criterion F: Inclusion of restored dune and riparian habitats reduces fragmentation and improves functional connectivity within the lower Ballona Creek ecosystem.
• Toes Beach Dune, while too small to warrant standalone SEA designation, represents a restored coastal dune system that gains ecological relevance through its connection to the expanded Ballona Wetlands SEA.

Cruzan Mesa Vernal Pools SEA (Subarea 5a)

Proposed:
Expand the SEA northward to major roads to encompass the full Cruzan Mesa landscape, including the complete vernal pool complex and adjacent uplands. The expansion captures associated unusual habitats, including eroding cliffs and adjacent alluvial plain features that contribute to the area’s ecological diversity.

Primary Ecological Justifications:

• Criterion A: Documented occurrences of tricolored blackbird, western spadefoot, Calochortus clavatus var. gracilis, and unarmored threespine stickleback (along Bouquet Canyon, per CNDDB).
• Criterion B/C: Concentrations of rare plants and wildlife associated with vernal pools, open grasslands, and wash habitats.
• Criterion E: Eroding sandstone cliffs provide unique nesting habitat for raptors and support specialized plant assemblages; the adjacent alluvial plain along Bouquet Canyon represents an uncommon grassland-wash complex within the Santa Clarita region.
• Expansion improves representation of the full ecological setting supporting the vernal pool system, rather than isolating pools from their surrounding upland and geomorphic context.

East San Gabriel Valley SEA (Subareas 6a – c, 6e – f)

Proposed:
Expand SEA to capture large blocks of open space with substantial areas of grassland, cactus scrub, coastal sage scrub, oak/walnut woodland, and riparian woodland. The hillsides south of Amar Road are especially valuable as expanses of intact cactus scrub occupied by a little-known population of coastal California gnatcatchers and cactus wrens (multiple pairs of both species documented in field visits). Extending the existing SEA just west of Grand Avenue to include Galster Wilderness Park and then south across Amar Road will incorporate a sycamore-willow riparian corridor that runs along North Lemon Avenue, which connects to a series of intact cactus scrub-covered hillsides that extend east back across Grand Avenue to the campus of Mt. San Antonio College. Proposed adjustments also add a 41-acre hillside of cactus scrub north of Puddingstone Reservoir.

Primary Ecological Justifications:

• Criterion A: Presence of coastal California gnatcatcher.
• Criterion B/C: Suitable habitat for numerous sensitive wildlife species now uncommon in coastal southern California, including cactus wren, burrowing owl, grasshopper sparrow.
• Criterion E: This cluster of several extensive stands of intact cactus scrub, occupied by multiple pairs of cactus wrens, is now unusual in the region, following years of intensive development, numerous wildfires, fuel modification actions, invasions of non-native plants, and, in some areas, overtopping of cactus by native and non-native plants, all of which continue to degrade the remaining areas of cactus scrub habitat.
• Criterion G: Designation would reduce habitat fragmentation and increase connectivity in an area that appears highly vulnerable to ongoing habitat loss around the edges (ongoing loss observed during field visits).

El Segundo Dunes SEA (Subarea 7a)

Proposed:
Expand the existing El Segundo Dunes CRA by adding an SEA that incorporates additional areas of native dune habitat that have been restored since the 2000 SEA update. The proposed expansion captures contiguous habitat that is ecologically similar to the currently designated SEA and supports the same suite of dune-dependent species and processes.

Primary Ecological Justifications:

• Criterion A: The expanded area represents a continuation of the same coastal dune habitat type that supports the endangered El Segundo blue butterfly.
• Criterion B/C: Restoration efforts have reestablished native southern dune scrub vegetation in this area, which is very uncommon in the southern California region, and represents an expansion of one of the rarest and most heavily impacted habitat types in Los Angeles County.
• Criterion D: The El Segundo Dunes support a concentration of species adapted to sandy, well-drained coastal dune habitats that depend on these environments to complete their full life cycles. The restored areas expand the extent of this specialized habitat and reinforce the ecological function of the existing SEA.

Griffith Park SEA (Subarea 8a)

Proposed:
Expand the SEA to include Hollywood Reservoir and surrounding hillsides and extend the boundary northward toward the Mulholland Drive Viaduct and Pilgrimage Bridge along Cahuenga Boulevard. These locations represent potential wildlife crossing points over the U.S. 101 Freeway.

Primary Ecological Justifications:

• Criterion B/C: Presence of locally rare plant species, including Juglans californica, and the ecological importance of open-water habitat within an otherwise upland-dominated landscape.
• Criterion D: Hollywood Reservoir supports a high concentration of water-dependent birds; over 200 avian species have been documented via eBird, substantially exceeding the species richness recorded for Griffith Park as a whole.
• Criterion G: The proposed expansion strengthens connectivity across Cahuenga Pass, supporting wildlife movement between Griffith Park and the eastern Santa Monica Mountains.

Joshua Tree Woodlands SEA (Subarea 10a)

Proposed:
Expand the SEA to include additional large parcels supporting intact Joshua tree woodland, areas with potential for natural regeneration, and adjacent habitat necessary to maintain ecological connectivity among currently fragmented habitat blocks and across the surrounding desert landscape. The current SEA consists of several fragmented blocks rather than a single contiguous area. The proposed expansion highlights key Joshua tree woodland parcels while improving linkage among disjunct habitat areas.

In addition, one small, isolated portion of the existing Joshua Tree Woodlands SEA near the northeast corner of the County is geographically separated from the primary woodland core and is surrounded by the San Andreas SEA and the proposed Liebre – Sierra Pelona SEA. Given its isolation and closer ecological relationship to these adjacent areas, this portion is proposed for reassignment to the Liebre – Sierra Pelona SEA. Consolidating this area, together with the proposed expansion, would allow for the remaining Joshua Tree Woodlands SEA to act as a more cohesive habitat block that supports existing woodland, regeneration potential, and habitat connectivity.

Primary Ecological Justifications:

• Criterion A: Documented occurrences of burrowing owl, Swainson’s hawk, and Joshua tree woodland; tricolored blackbird may also occur in associated habitats.
• Criterion B/C: Supports numerous rare and locally uncommon species, including LeConte’s thrasher and Scott’s oriole.
• Criterion E: Represents the westernmost expression of clonal Joshua tree (formerly Yucca brevifolia var. herbertii) woodland, along with sandy wash systems containing scattered riparian elements such as large cottonwoods that are uncommon in the central Antelope Valley.
• Criterion G: Provides important east – west connectivity and movement opportunities for wildlife, particularly in a landscape increasingly constrained by industrial-scale solar development in adjacent Kern County.

Palos Verdes Peninsula & Coastline SEA (Subareas 13a – 13t)

Proposed:
Expand existing coastal SEA boundaries to improve continuity along the peninsula, connect isolated inland canyon SEAs, and incorporate additional biologically significant areas. Proposed expansions include all extant populations of the Palos Verdes blue butterfly (i.e., Malaga Dunes, the Chandler Preserve, and the former Defense Fuel Support Point site); White Point Preserve, which supports coastal California gnatcatchers and a wide variety of raptors; and coastal bluff habitats that support rare plants and sensitive natural communities.

Primary Ecological Justifications:

• Criterion A: Presence of coastal California gnatcatcher at several sites and all known extant populations of the Palos Verdes blue butterfly (three sites).
• Criterion B/C: Coastal bluff habitats support rare plant species and natural communities, such as Aphanisma blitoides and Atriplex pacifica. Slopes of cactus scrub may be occupied by cactus wrens.
• Criterion E: The expanse of sandy soils well inland from the coast at Malaga Dunes, vegetated with Acmispon glaber and Croton californica, is a unique habitat in the County that supports a wide variety of insect life, including the critically endangered Palos Verdes blue butterfly.
• Criterion G: Several biologically important areas currently fall outside existing SEA boundaries, resulting in fragmentation and exclusion of key resources.
• Natural canyon systems with intact vegetation provide opportunities to connect small, isolated SEA polygons and improve functional ecological continuity across the peninsula.
• Boundary refinements improve representation of the full coastal – upland ecological gradient characteristic of the Palos Verdes Peninsula.

Puente Hills SEA (Subareas 15a – 15j)

Proposed adjustments to the Puente Hills SEA occur in several geographically distinct areas along the northern, eastern, and western portions of the existing SEA. Subareas areas are described below and correspond to the labeled subareas areas shown on the map below.

Note that Interstate 605 forms a substantial geographic and anthropogenic barrier between the western and eastern portions of the existing SEA. As a result, the habitats associated with the Whittier Narrows / San Gabriel River corridor and those associated with the Puente Hills uplands function as largely separate ecological systems within the current designation.

Subareas 15b – d and 15i. Colima Rd to SR 57

Proposed:
Add three small areas along the northern border of the SEA, containing oak woodlands and non-native grassland comparable to nearby designated areas (Subareas 15b – d). Adding these four areas of SEA-quality habitat that were previously excluded for unknown reasons increases the intactness of the SEA by making the boundary more uniform and consistent with the edge of urban development (no apparent justification exists for excluding them).

Add the undisturbed part of Schabarum Park, consisting of 23 acres of intact cactus scrub and coastal sage scrub (15i). This would expand rare habitat (cactus-rich coastal sage scrub) for two protected bird species, the coastal California gnatcatcher and the cactus wren, and expand habitat protection for the intermediate mariposa lily.

Primary Ecological Justifications:

• Criterion A: Presence of coastal California gnatcatcher and cactus wren in existing parkland located close to the currently designated SEA (Schabarum Park). Habitat for mountain lion, white-tailed kite and intermediate mariposa lily.
• Criterion B/C: Habitat occupied by cactus wren (pair observed during field visit near Schabarum Park) and likely other special-status species occur in expansion areas, including grasshopper sparrow and red diamond rattlesnake.

Subareas 15e – f. San Gabriel River

Proposed:
Above Whittier Narrows, add 8.3 acres of the San Gabriel River channel that supports willow scrub habitat indistinguishable from adjacent habitat that is designated as SEA. The justification for this small addition is to include an area of vireo-occupied riparian habitat that is contiguous with the existing SEA.

Downstream of Whittier Narrows Dam, add a 1.6-mile segment of the river channel, most of which is vegetated with riparian vegetation consistently occupied by nesting least Bell's vireos and other special-status birds (e.g. yellow-breasted chat and northern yellow warbler). Also add the spreading grounds between Washington and Whittier Boulevards (Subarea 15f).

With these two additions, the SEA would include the full range of important bird habitats along the middle segment of the San Gabriel River, from Washington Boulevard north through Whittier Narrows to just above the confluence with San Jose Creek. Farther upstream, riparian habitat is less contiguous and varies in its distribution from year to year, and this area is not recommended for addition.

Primary Ecological Justifications:

• Criterion A: Least Bell’s vireos nest in all riparian vegetation recommended for addition.
• Criterion B/C: Yellow-breasted chats and northern yellow warblers are special-status birds that also nest in the riparian woodlands recommended for addition.
• Criterion D: The San Gabriel River spreading grounds host large concentrations of ducks, shorebirds, and gulls, seasonally. A total of 243 bird species has been recorded at the spreading grounds (eBird), attesting to their significance as stopover habitat for many species and wintering habitat for others.
• Criterion E: Riparian woodlands occupied by least Bell’s vireos and large expanses of shallow water usable by large numbers of birds are both rare habitats in the County.
• Criterion G: The San Gabriel River channel is an important conduit for the movement of wildlife through the region, with high potential for restoration (including “Emerald Necklace” planning process).

Subareas 15g – h. Legg Lake to Montebello Hills

Proposed:

Expand the SEA from Rio Hondo east and west to include valuable natural habitats, including the three Legg Lake basins, thereby bolstering habitat connectivity through the somewhat fragmented segment of the Puente Hills SEA lying between Whittier Narrows and the Montebello Hills.

Coastal California gnatcatchers are found in the proposed addition areas both east and west of Rio Hondo. The area east of Rio Hondo supports least Bell’s vireo, yellow-breasted chat, northern yellow warbler, and coastal California gnatcatcher, and a population of Centromadia parryi ssp. australis (CRPR 1B.1). Legg Lake has important heron and cormorant rookeries and provides habitat for a wide variety of resident, wintering, and migratory birds.

Primary Ecological Justifications:

·         Criterion A: Documented occurrences of least Bell’s vireo, coastal California gnatcatcher, and Centromadia parryi ssp. australis.

·         Criterion B/C: Presence of riparian woodland, moist meadow, and associated wetland habitats that are uncommon within the urbanized Los Angeles Basin. Yellow-breasted chat and northern yellow warbler also nest in this area.

·         Criterion D: Legg Lake supports significant waterbird nesting and roosting activity, including heron and cormorant rookeries.

·         Criterion G: The proposed expansion strengthens connectivity between the Whittier Narrows, Rio Hondo corridor, and downstream open-space networks, facilitating wildlife movement into and through the Los Angeles Basin.

·         Inclusion of Legg Lake integrates an ecologically functional wetland complex that complements the existing SEA and enhances its landscape-scale value.

Subarea 15j. Diamond Bar/Tres Hermanos

Proposed:
Expand the SEA to incorporate large, contiguous open-space areas including Tres Hermanos Ranch, Pantera Park, Summitridge Park, Sycamore Canyon Park.

Primary Ecological Justifications:

• Criterion A: Presence of coastal California gnatcatcher and tricolored blackbird.
• Criterion B/C: Habitat for numerous sensitive wildlife species now uncommon in coastal southern California, including golden eagle, northern harrier, grasshopper sparrow, cactus wren, and historically, long-eared owl and burrowing owl; potential habitat for western spadefoot toad in grasslands and western pond turtle in and around wetlands.
• Criterion D: Supports nesting tricolored blackbird colonies in some years.
• Criterion E: Captures extensive grassland, freshwater wetland, and un-channelized riparian habitats that have largely disappeared from coastal southern California.
• Criterion G: Represents a major landscape-scale connectivity opportunity linking the Puente Hills SEA to the San Gabriel Mountains, including headwaters of Tonner Canyon.
• Tres Hermanos Ranch functions as important golden eagle foraging habitat and anchors the southern portion of the proposed expansion.

San Andreas SEA (Subareas 17b – 17d)

Proposed:
Substantially expand and refine the boundaries of the San Andreas SEA to incorporate large, ecologically intact landscapes associated with the San Andreas Rift Zone and adjacent desert – montane transition areas. Proposed changes include two minor boundary adjustments: 17d extends the boundary eastward to Highway 14 west of Lake Palmdale, incorporating a critical movement barrier with high potential for enhanced connectivity. The proposed expansion also addresses a long-standing gap between the San Andreas SEA and Joshua Tree Woodlands SEA and incorporates extensive open space that remains lightly developed. Portions of the landscape extend toward Tejon Ranch and include contiguous, high-quality habitat that was previously excluded.

Two larger areas are proposed for expansion to more fully include the flatter portions of the open grassland and wildflower field habitats protected within the Antelope Valley California Poppy State Reserve: Subarea 17b, which forms a broader band surrounding the existing SEA, and Subarea 17c, which extends east and northeast of Quail Lake to include extensive, undisturbed habitats of the southern Tehachapi Mountains.

Many of the grassland species—particularly birds—for which this SEA was established, prefer flat terrain rather than hilly or mountainous topography. Examples include special-status species such as Swainson’s hawk, short-eared owl, burrowing owl, and tricolored blackbird, as well as species of local interest such as wintering flocks of mountain bluebirds, horned larks, and vesper sparrows, breeding western meadowlarks, and a variety of wintering raptors. Expanding the SEA to include these flat areas would help ensure adequate habitat as development continues to expand in the Antelope Valley. Subarea 17c east of Quail Lake also contains several areas of high rare plant species richness, among the highest in the county, and supports regular flyovers by California condors.

Primary Ecological Justifications:

• Criterion A: An exceptional diversity of special-status species is found within the San Andreas SEA, including pond turtle (Actinemys sp.; species-level identification uncertain in the contact zone between A. marmorata and A. pallida) in small montane wet meadows (sag ponds), burrowing owl, Swainson’s hawk, California condor, Joshua tree woodland (throughout), tricolored blackbird (throughout), vernal pool fairy shrimp, and numerous sensitive plant taxa (e.g., Astragalus leucolobus, Calochortus palmeri var. palmeri, Navarretia setiloba).
• Criterion B/C: Supports diverse and often declining plant and wildlife assemblages, including rare grassland birds, uncommon herpetofauna and mammals, an exceptional diversity of locally rare plants, and high-value riparian wildlife communities with strong restoration potential.
• Criterion D: Constructed wetlands and riparian areas provide critical habitat in an otherwise arid landscape, acting as focal resources for wildlife.
• Criterion E: Represents the western edge of Joshua tree woodland (clonal form), extensive sandy wash systems with scattered riparian elements (including large cottonwoods), rare riparian woodlands in arid settings, and one of the most significant remaining native grassland systems in Los Angeles County.
• Criterion F: Encompasses large, remote, and largely undeveloped landscapes with little recent human disturbance, supporting wide-ranging species and intact ecological processes.
• Criterion G: With the recommended adjustments, this SEA will better function as a major regional connectivity hub, facilitating wildlife movement between the Antelope Valley, San Gabriel Mountains, and Tehachapi Mountains, including crossings over the California Aqueduct and Interstate 5. The area can also accommodate climate-driven range shifts and lateral movement across desert, grassland, and montane habitats.

San Dimas Canyon/San Antonio Wash SEA (Subareas 18a – 18c)

Proposed:
Expand the SEA to include Padua Hills, filling the gap between Marshall Canyon and San Antonio Wash; extend coverage downslope from the U.S. Forest Service boundary to include high-value riparian, coastal scrub, chaparral, and oak woodland habitats at the urban edge near La Verne; and extend coverage into the eastern Glendora foothills.

The existing gap between Marshall Canyon and San Antonio Wash excludes large, contiguous areas of chaparral, oak woodland, and riparian habitat, including protected lands such as Claremont Wilderness Park. Incorporating Padua Hills and adjacent parcels (including the Anabi parcel) would extend SEA coverage into areas supporting important biological resources and improve continuity between currently designated areas. Extending the boundary downslope from the U.S. Forest Service lands to the urban edge would also capture intact habitat mosaics that currently occur between the national forest boundary and developed areas, improving continuity of habitat rather than leaving isolated fragments.

Primary Ecological Justifications:

• Criterion A: Occurrences of sensitive plant and wildlife species, including Berberis nevinii, Calochortus clavatus var. gracilis, Brodiaea filifolia, coastal California gnatcatcher, and other regionally important taxa.
• Criterion B/C: Supports strong populations of sensitive wildlife and plant communities, including cactus wren, Engelmann oak, and extensive walnut woodland.
• Criterion E: Contains unique clay-soil grasslands supporting brodiaea and hybrid oak assemblages that are uncommon in the County.
• Criterion F: Portions of the proposed expansion remain relatively undisturbed due to limited public access and lack of intensive development.
• Criterion G: While not a primary long-distance movement corridor, the area contributes to local connectivity by maintaining continuity between canyon, foothill, and riparian habitats.

San Gabriel Canyon SEA (Subareas 19a – 19b)

Proposed:
Expand the SEA westward to include the western Glendora foothills extending through Azusa, and extend coverage downslope to include alluvial fan and wash-associated habitats adjacent to the San Gabriel River, including Van Tassel Canyon.

The existing SEA boundary leaves a substantial gap between the national forest and the urban edge, excluding ecologically connected foothill and wash habitats. Expanding the boundary downslope would incorporate these connected landscapes and improve continuity between upland habitats and the San Gabriel River wash. Inclusion of Van Tassel Canyon and adjacent alluvial areas further strengthens ecological linkage between the river corridor and surrounding foothills, addressing a long-standing omission in SEA coverage.

Primary Ecological Justifications:

• Criterion A: Documented occurrences of sensitive plant species such as Brodiaea filifolia and Symphyotrichum greatae, with potential occurrences of additional sensitive Dudleya taxa.
• Criterion B/C: Supports a diverse assemblage of sensitive wildlife and plant communities, including cactus wren, Engelmann oak, walnut woodland, and rare alluvial fan scrub habitats, despite recent disturbance from wildfire.
• Criterion E: Contains unique clay-soil grasslands with brodiaea and hybrid oak swarms, along with alluvial fan systems that are increasingly rare in the County.
• Criterion F: Portions of the area remain relatively undisturbed due to limited access and rugged terrain.
• Criterion G: Serves as an important east – west (lateral) movement zone along the base of the San Gabriel foothills, particularly for low-elevation species moving between wash and upland habitats.

Subarea 20a. Newhall Ranch West

The Santa Clara River-associated habitats near the Ventura County line are now recognized as supporting a notable concentration of rare species. Although portions of these resources are expected to be retained as open space within the Newhall Ranch community, this expansion area acknowledges their presence and ecological importance within a landscape undergoing development.

Primary Ecological Justifications:

• Criterion A: Western spadefoot, least Bell's vireo, Calochortus clavatus var. gracilis, Chorizanthe parryi var. fernandina,
• Criterion B/C: Major concentrations of rare plant species richness; several coastal-slope bird species of local concern (e.g., greater roadrunner, loggerhead shrike).
• Criterion E: Valley oak savanna occurs near the southern and eastern extent of its range.

Subarea 20b. Golden Valley Rd.

Located near the geographic center of Santa Clarita, the hills and drainages along Golden Valley Road represent a microcosm of habitats found along the Santa Clara River. Despite its location within an incorporated city, this subarea retains relatively intact habitat and includes one of the few remaining vernal pools on the coastal slope of Los Angeles County, supporting species that have been widely lost elsewhere.

Primary Ecological Justifications:

• Criterion A: Western spadefoot, vernal pool fairy shrimp, Navarretia fossalis, Calochortus clavatus var. gracilis.
• Criterion B/C: Scattered occurrences of rare plants such as Calochortus plummerae (no concentrated richness hotspots); several coastal-slope bird species of local concern (e.g., greater roadrunner, loggerhead shrike)).
• Criterion D: The vernal pool habitat in this subarea represents a limited habitat type within the County and region and serves as seasonal breeding habitat.
• Criterion G: Important local movement area for species moving from the Santa Clara River wash into adjacent hills and tributaries, providing connectivity through an urbanizing landscape.

Subareas 20c – e. Newhall Ranch boundary

These boundary adjustments incorporate preserved open-space areas within the Newhall Ranch development that were not included in the 2000 SEA boundaries. Including these areas improves continuity along the Santa Clara River corridor and reflects retained habitat and connectivity within the developed landscape.

Subarea 20f. Castaic North (Subarea 20f)

Castaic Lagoon, and to a lesser extent Castaic Reservoir, support large numbers of waterbirds, particularly during winter. The rugged hills and canyons surrounding Castaic Reservoir and Castaic Lagoon are now recognized as supporting a diverse assemblage of sensitive natural communities and species, ranging from California condor to coastal California gnatcatcher. Recent biological surveys associated with proposed development have documented numerous rare plant species within the grassland and scrub communities, many of which have experienced substantial losses farther south in the Los Angeles Basin. Much of this area remains difficult to access, and its full ecological significance is not yet fully documented.

Primary Ecological Justifications:

• Criterion A: Western spadefoot, California condor, burrowing owl, coastal California gnatcatcher, least Bell's vireo, Calochortus clavatus var. gracilis.
• Criterion B/C: Major concentrations of rare plant species richness; several coastal-slope bird species of local concern (e.g., greater roadrunner, loggerhead shrike).
• Criterion D: Castaic Lagoon supports concentrations of waterbirds; rock outcrops provide raptor nesting habitat.
• Criterion E: Major transition area between coastal and montane ecosystems (e.g., coastal sage scrub, chamise chaparral)
• Criterion F: Extensive roadless areas, including some of the most rugged backcountry areas close to Los Angeles (upper Castaic Creek, Fish Canyon)
• Criterion G: Important wildlife movement area across Interstate 5 for species with a range of ecological requirements.

Subarea 20g. Agua Dulce – Acton

This large expansion area would primarily improve ecological connectivity between the Sierra Pelona and the San Gabriel Mountains, both proposed as new SEAs. Substantial areas of natural habitat remain, including alluvial washes, juniper woodland, rock outcrops, and wildflower fields. Although these resources are more widely distributed than those in some other proposed expansion areas, the subarea occupies an important coastal – desert transition zone also represented in portions of the Barrel Springs subarea (3i) and the broader Santa Clara River SEA. Accordingly, the primary function of this expansion is to enhance wildlife movement and ecological connectivity between mountain ranges, rather than to capture unique or localized resources.

Primary Ecological Justifications:

• Criterion B/C: Scattered occurrences of rare plants (no concentrated richness hotspots); several coastal-slope bird species of local concern (e.g., greater roadrunner, loggerhead shrike).
• Criterion D: Rock outcrops scattered throughout the subarea provide nesting habitat for raptors.
• Criterion E: Western extent of Mojave Desert flora and fauna transitioning toward the coastal slope (Acton Wash and associated drainages and slopes).
• Criterion G: Large contiguous open-space area connecting the Liebre – Sierra Pelona and San Gabriel Mountains, including remaining open space on both sides of Highway 14

Subarea 20h. Valley Oaks Savannah

Subarea 20h incorporates the former Valley Oaks Savannah SEA into the expanded Santa Clara River SEA. This area supports a remnant stand of valley oak woodland and represents an ecologically important component of the broader Santa Clara River landscape, improving continuity between riverine and adjacent upland habitats.

Santa Monica Mountains SEA (Subareas 22a – 22b)

Proposed:

Minor adjustment of the SEA boundary northeast of the San Monica Mountains SEA to include approximately 22.2 acres along a ridge south of the Caballero Country Club (22a) and approximately 700 acres encompassing Serrania Park and Corbin Canyon (22b). These areas contain habitat comparable to that within the adjacent SEA and, in the case of Serrania-Corbin Canyon, include relatively intact walnut woodland and other low-elevation habitats that remain less developed than portions of the SEA to the south. Inclusion of these areas would also strengthen an important east-west movement zone along the northern base of the eastern Santa Monica Mountains for species such as mule deer and mountain lions.

Santa Susana Mountains/Simi Hills SEA (Subareas 23a – d)

Proposed:

Minor adjustment of the SEA boundary in four localized areas (Subareas 23a – d) to incorporate adjacent natural habitat and improve connectivity along the southeastern margin of the existing SEA. These refinements include approximately 167 acres south of San Fernando Road/Interstate 5 and west of Balboa Boulevard, encompassing a hillside that supports a large population of Lupinus paynei (CRPR 1B.1) and southern California black walnut woodland. Additional adjustments capture adjacent undeveloped hillsides and habitat patches that would improve continuity of natural vegetation and strengthen potential linkage with nearby open space to the east and northeast. Inclusion of these areas would extend the SEA boundary toward the Balboa Boulevard bridge over Interstate 5 and reduce fragmentation along the urban interface.

Verdugo Mountains SEA (Subareas 27a – e, 27h – o)

Proposed:

Minor adjustment of the SEA boundary to include 12 small areas located around the margins of the existing SEA. These areas contain habitat conditions comparable to those within the adjacent SEA—including intact, high-quality coastal sage scrub—and appear to have been excluded from the existing designation due to mapping limitations or boundary simplification. Situated along the interface between the Verdugo Mountains and surrounding development, these areas are particularly vulnerable to degradation from fuel modification, vegetation clearing, and other forms of disturbance. Inclusion of these areas would improve the consistency of the SEA boundary.

Baldwin Hills Proposed SEA (BH)

General location and landform

The Baldwin Hills extends over roughly two square miles on the floor of the Los Angeles Basin, just east of Los Angeles International Airport. It is located within the lower Ballona Creek Watershed south of the creek channel, which historically formed a large complex of sloughs and marshes (“ciénegas”) centered east of the hills. The hills themselves were uplifted from the sedimentary soil of the basin floor, and form the northern terminus of a series of low hills extending north along the Newport – Inglewood Fault. The northern face of the hills is steep, while the southern edge features low ridges and incised canyons.

Coastal scrub vegetation within the 1,000-acre Inglewood Oil Field has been free of most human disturbance for more than a century, as this entire property is fenced. From the outside, one may see large cactus patches, Dudleya (cf. lanceolata), and other elements that have been lost in other open space patches on the Los Angeles Basin floor. So, while oil operations have continued, most other impacts, such as trampling and human disturbance, have been minimal.

The proposed SEA is located within the Beverly Hills, Hollywood, Venice, and Inglewood United States Geological Survey (USGS) 7.5' California Quadrangles.

Surrounded by dense urban development, the Baldwin Hills represent a mosaic of ownership and land uses, including the following areas with native/natural vegetation:

-       Inglewood Oil Field (c. 1000 acres, a mix of active oil extraction areas and pockets of native coastal sage scrub and seasonal wetland vegetation).

-       Kenneth Hahn State Regional Park (401-acre recreational area with considerable reserves of native coastal sage scrub habitat, east of La Cienega Blvd.).

-       Baldwin Hills Scenic Overlook State Park (8.5-acre park with active habitat restoration program, south of Jefferson Blvd.).

-       Stoneview Nature Center (5-acre park west of La Cienega Blvd.).

-       Holy Cross Cemetery (200-acre, largely manicured area of lawn and planted trees, but with a portion of undeveloped habitat toward the back/northern end).

Biological Resources

Vegetation and natural communities

The Baldwin Hills represent the most significant reserve of low-elevation coastal scrub habitat in Los Angeles County away from the Palos Verdes Peninsula. Although this scrub contains little sage (Salvia spp.), it does have a strong component of California buckwheat (Eriogonum fasciculatum) and a prickly-pear cactus (Opuntia cf. littoralis). A more mesic scrub is present on north-facing slopes and at seeps, notably containing blue elderberry (Sambucus mexicana), giant wildrye (Elymus condensatus) and western poison-oak (Toxicodendron diversilobum). Notable plant occurrences include relict stands of purple needlegrass (Stipa pulchra), greenbark ceanothus (Ceanothus spinosus), and the only documented occurrence of Nuttall’s scrub oak (Quercus dumosa), a CNPS Rare plant, in Los Angeles County.

While the hills still support isolated populations of many lowland wildlife species, including gray fox (Urocyon cinereoargenteus), regionally-rare wildlife species have been extirpated over time, with notable losses including San Diego black-tailed jackrabbit (Lepus californicus bennettii)—last recorded in 2000—and cactus wren (Campylorhynchus brunneicapillus), last seen in 1996. However, the Federally Threatened coastal California gnatcatcher (Polioptila californica californica) appears to be established now, with regular sightings of multiple individuals. The red coachwhip (Masticophis flagellum piceus) also maintains a small population in the hills based on photos uploaded to iNaturalist, completely isolated from nearest populations in the Long Beach and Whittier Narrows area. The Trask shoulderband snail (Helminthoglypta traskii) appears to be common here, which has a NatureServe Rank of S2 (Imperiled, at high risk of extirpation in the state due to restricted range, few populations or occurrences, steep declines, severe threats, or other factors), as is Crotch’s bumblebee (Bombus crotchii), a Candidate for State listing. Southern California black walnut (Juglans californica, CNPS Rank 4) also occurs, within mesic scrub, isolated from nearest occurrences by several miles.

Many raptor nests are present, with all the known species found in the Los Angeles area present and either nesting, or suspected of doing so (e.g., American kestrel (Falco sparverius), American barn owl (Tyto furcata)).

Wildlife Movement

Major connectivity opportunities exist along the Ballona Creek channel to and from the Ballona Wetlands/El Segundo Dunes (both SEAs), which otherwise would be completely isolated. In addition, the entire Baldwin Hills are the largest patch of habitat between the Palos Verdes peninsula and the Santa Monica Mountains, so function as a “stepping stone” between these two largely protected areas.

Designation Criteria

The following table identifies which of the six existing SEA Selection Criteria and the proposed new SEA Selection Criterion are satisfied by the proposed SEA.

Criteria Summary of the Proposed Baldwin Hills SEA

Colorado Lagoon Proposed SEA (CL)

General location and landform

Historically a component of the greater Los Cerritos Wetlands, Colorado Lagoon is located in the southeastern corner of the City of Long Beach, where it feeds into upper Alamitos Bay at Marine Stadium. The existing 18-acre lagoon and six acres of associated natural uplands are currently being expanded by another six acres through an ambitious project to daylight and restore an open channel to Alamitos Bay that was filled in decades ago. In addition to expanding the area of natural habitat by 25 percent, the intent of the open channel project is to improve tidal circulation in the lagoon to better support stands of eelgrass that were restored as part of the above-mentioned improvements. At the time of the last SEA update, in 2000, Colorado Lagoon consistently ranked among the most polluted and impaired coastal water bodies in Los Angeles County, and it was not known to have high ecological values. The lagoon has since undergone extensive improvements to remove toxic sediments, filter and re-route urban runoff before it enters the lagoon, and restore coastal marsh and native upland scrub around the water’s edge, actions that have dramatically improved habitat conditions during the last decade.

The proposed SEA is located within the Downey United States Geological Survey (USGS) 7.5' California Quadrangle.

Although not a formal SEA Selection Criterion, it is relevant that wetlands historically associated with the San Gabriel River, including Colorado Lagoon, are considered crucial to the Gabrieleño-Kizh/Tongva and Juaneño/Acjachemen peoples, for whom the permanent coastal settlement of Puvunga, including Motuucheyngna, is recognized as a major, sacred site of emergence. As such, formal recognition of the ecological significance of Colorado Lagoon through SEA designation would be consonant with and respectful of TEK.

The first phase of community-based restoration at Colorado Lagoon lasted from 2008 to 2011, when volunteers manually removed 25,000 pounds of non-native invasive ice plant (various species) and installed 3,500 native plants in about two acres of intertidal wetlands and low-lying uplands on the lagoon’s eastern shore. The second and third phases of restoration, addressing the lagoon’s western arm, continued through 2014.

Biological Resources

Vegetation and natural communities

In its improved incarnation, Colorado Lagoon is widely recognized as an important area for avian life. Birders have documented more than 240 bird species there, including regular sightings of Endangered California least terns (Sterna antillarum browni) during the summer, when adults bring fish from the lagoon to their colony at nearby Anaheim Bay to the south. On occasion, the terns will bring recently fledged young to the lagoon.

Piscivorous species found at the lagoon year-round include California brown pelicans (Pelicanus occidentalis californicus), double-crested cormorants (Nannopterum auritum), snowy egrets (Egretta thula), and pied-billed grebes (Podilymbus podiceps). During winter, dozens of Lesser Scaup (Aythya affinis) can be found bobbing on the surface, often accompanied by such species as American wigeon (Mareca amercana), redhead (Aythya americana), bufflehead (Bucephala albeola), and ruddy duck (Oxyura jamaicensis), and flocks of several dozen gulls congregate along the southern shore daily. Shorebirds utilize the lagoon daily, mainly during migration, when least and western sandpipers pass through along with such larger species as the willet (Tringa semipalmata), marbled godwit (Limosa fedoa), and long-billed curlew (Numenius americanus).

Below the water's surface, the lagoon functions as a natural fish hatchery. It supports approximately 21 species of marine fish, such as the California halibut (Paralichthys californicus), yellowfin croaker (Umbrina roncador), and gray smooth-hound (Mustelus californicus), as well as bat rays (Myliobatis californica) and Haller’s round rays (Urobatis halleri). These populations benefit from the lagoon’s eelgrass beds, which provide essential nursery grounds and hunting territory for predatory species, and which are now very rare in southern California. The benthic environment is equally rich, inhabited by a variety of invertebrates including striped shore crabs, clams, and sea slugs. Visitors often observe moon jellies drifting near the shoreline or washing up on the sandy beaches, a testament to the lagoon's direct tidal exchange with Alamitos Bay. The beaches provide habitat for s-banded (Cicindela trifasciata) and wetsalts tiger beetles (Cicindelidia hemorrhagica). Also resident is the wandering [saltmarsh] skipper (Panoquina errans), with a NatureServe Rank of S2 (Imperiled, at high risk of extirpation in the state due to restricted range, few populations or occurrences, steep declines, severe threats, or other factors).

Rimming the lagoon is a band of intertidal wetland (a habitat widely lost in the region), including at least 17 native salt marsh plant species. Restoration projects have replaced invasive flora with such southern California natives as coastal goldenbush (Isocoma menziesii), California sunflower (Encelia californica), dune buckwheat (Eriogonum parvifolium), and giant coreopsis (Leptosyne gigantea), which provide habitat for a variety of butterflies, bees, wasps, spiders and other invertebrates that provide prey for resident songbirds such as common yellowthroats (Geothlypis trichas). Sensitive and noteworthy plant species include woolly seablite (Suaeda taxifolia) and southwestern spiny rush (Juncus acutus ssp. leopoldii), both California Rare Plant Rank 4.2 (watch list).

Wildlife movement

Colorado Lagoon is not located along any terrestrial wildlife movement corridor or habitat linkage, but it does function as an important stopover site for a variety of shorebirds during spring and fall migration periods.

Designation Criteria

The following table identifies which of the six existing SEA Selection Criteria and the proposed new SEA Selection Criterion are satisfied by the proposed SEA.

Criteria Summary of the Proposed Colorado Lagoon SEA

El Dorado Regional Park Lakes Proposed SEA (ED)

General location and landform

El Dorado Regional Park, covering more than 600 acres in the City of Long Beach, features a series of natural lakes historically associated with swamps of the lower San Gabriel River, which were extensive prior to its channelization in the mid-twentieth century. The 135 acres of the park that are proposed for SEA designation include six hydrologically connected lakes in Areas 1, 2, and 3 of the park, which constitute rare and especially valuable freshwater wetland habitats in coastal Los Angeles County. The surrounding developed parts of the park are not recommended for SEA designation.

The proposed SEA is located within the Downey United States Geological Survey (USGS) 7.5' California Quadrangle.

Although not a formal SEA Selection Criterion, it is relevant that wetlands historically associated with the San Gabriel River, including those in El Dorado Regional Park, are considered crucial to the Gabrieleño-Kizh/Tongva and Juaneño/Acjachemen peoples, for whom the permanent coastal settlement of Puvunga, including Motuucheyngna, is recognized as a major, sacred site of emergence. As such, formally recognizing the ecological significance of these natural lakes and connecting waterways through SEA designation would be consonant with and respectful of TEK.

Biological Resources

Vegetation and natural communities

Considered as a whole, El Dorado Regional Park is known to provide important habitat for birds, with eBird records documenting more than 240 species. Along with large numbers of resident waterfowl, ducks found at the lakes during fall and winter include American wigeon (Mareca americana), gadwall (M. strepera), northern shoveler (Spatula clypeata), and ruddy ducks (Oxyura jamaicensis). Three California Species of Special Concern, the least bittern (Botarus exilis), Clark’s marsh wren (Cistothorus palustris clarkae), and northern yellow warbler (Setophaga aestiva), nest in and around the lakes. Other wetland-dependent nesting species include great blue (Ardea herodias) and green (Butorides virescens) herons, and tree swallows. Lucky morning-glory (Calystegia felix), a species thought to be extinct until being rediscovered in Chino, San Bernardino County, in 2011, has since been found at Area 1 of El Dorado Regional Park (the Nature Center), where a few small populations persist as reminders of the park’s heritage as part of an extensive natural swamp.

The lakes support some extensive stands of emergent freshwater marsh habitat characterized by native California bulrush (Schoenoplectus californicus) and broad-leaf cattail (Typha latifolia), mixed with smaller amounts of various herbs, such as salt marsh fleabane (Pluchea odorata). Native trees growing around the margins of some of the lakes include black and arroyo willow (Salix gooddingii, S. lasiolepis).

Wildlife movement

El Dorado Regional Park is contiguous with the paved channel of the lower San Gabriel River. This channel and that of the Los Angeles River, several miles to the west, are the only geographic features connecting the southern coast of Los Angeles County to SEAs and other natural areas located 15 or more miles inland.

Designation Criteria

The following table identifies which of the six existing SEA Selection Criteria and the proposed new SEA Selection Criterion are satisfied by the proposed SEA.

Criteria Summary of the Proposed El Dorado Regional Park Lakes SEA

Liebre-Sierra Pelona Proposed SEA (LSP)

General location and landform

Located in the northwestern portion of the County, Liebre Mountain and the Sierra Pelona extend the Transverse Range west toward the Coast Ranges that begin in Ventura County.

Together with the San Gabriel Mountains to the east, most of the land here is owned by the federal government and managed by the U.S. Forest Service as four separate Districts comprising Angeles National Forest. The Forest boundary encompasses roughly 700,000 acres of Los Angeles County’s 3 million total acres, stretching from the far northwestern corner near Gorman, southeast to Claremont at the San Bernardino County line (the San Gabriel Mountains extend several miles east into San Bernardino Co.). The Forest consists of two large, unconnected blocks of territory, bisected by S.R. 14 and the Santa Clara River. These mountains contain most of the County’s undeveloped open space, and nearly all its large roadless areas. Private lands with clusters of houses are limited in the Liebre-Sierra Pelona, but the communities of Green Valley and Bouquet Canyon are exceptions. The Liebre-Sierra Pelona also encompasses restored wet meadows and former golf course lands east of Elizabeth Lake where decommissioning of the golf course allows reestablishment of riparian and meadow habitats that were historically displaced;

Like the San Gabriel Mountains, the Liebre-Sierra Pelona supported a rich Indigenous history, with native peoples taking full advantage of the available game and abundant fruits such as acorns (Quercus spp.), chia (Salvia columbariae), and manzanita (Arctostaphylos spp.). Trading routes and footpaths for seasonal movements were extensive, connecting different portions of the mountains, and villages, with the lowlands to the north and south.

Biological Resources

Vegetation and natural communities

Like the San Gabriel Mountains to the east, the vegetation of the Liebre-Sierra Pelona is exceptionally diverse. The peaks are lower in this range (none exceeding 6,000’, vs. several over 9,000’ in the San Gabriel Mountains), with more oak woodland and less truly montane habitat. As in the San Gabriels, small sag ponds forming marshy meadows are located along the northern base of the range, but just one main watershed dominates (Santa Clara River). Many Californian tree and shrub species typical of the Sierra foothills reach the southern extent of their global range within the Sierra Pelona, including California buckeye (Aesculus californica), gray pine (Pinus sabiniana), blue oak (Quercus douglasii), and foothill gooseberry (Ribes quercetorum). The oak (Quercus) species diversity in particular is exceptionally high here, as the range represents a crossroads of Sierran, Coast Range, Mojave, and southern California woodland flora. Finally, interesting desert extensions of species are frequently encountered here, with populations of western Joshua tree (Yucca brevifolia) and Scott’s oriole (Icterus parisorum) found amid oak woodland and alluvial scrub habitat toward the northwestern corner of the range.

While most of the Threatened and Endangered high montane species of the San Gabriel Mountains are absent in the Liebre-Sierra Pelona, this range supports significant populations of arroyo toad (Anaxyrus californicus), California red-legged frog (Rana draytonii), California condor (Gymnogyps californianus), California spotted owl (Strix occidentalis occidentalis), and golden eagle (Aquila chrysaetos). Unarmored threespine stickleback (Gasterosteus aculeatus williamsoni) historically occurred and have been reintroduced to San Francisquito Canyon. County- and regionally rare bird populations of the Liebre-Sierra Pelona include likely nesting belted kingfisher (Megaceryle alcyon) in the upper Piru Creek drainage near the Ventura Co. line.

While the San Gabriel Mountains support more State and Federally protected plant species, Ross pitcher sage (Lepechinia rossii) is apparently endemic to the Liebre-Sierra Pelona, which support many regionally-rare plants, and those with small global ranges, including Robbin’s nemacladus (Nemacladus secundiflorus var. robbinsii), Tehachapi monardella (Monardella linoides ssp. oblonga), Johnson’s monkeyflower (Diplacus johnstonii), Mount Pinos larkspur (Delphinium parryi ssp. purpureum), and Peirson’s morning-glory (Calystegia peirsonii).

The nesting raptor community of the Liebre-Sierra Pelona appears to be highly diverse, with historical nesting sites for California condor (Red Mountain), and breeding-season records of some of the County’s rarest nesting raptors, including prairie falcon (Falco mexicanus), long-eared owl (Asio otus), and northern saw-whet owl (Aegolius acadius).

Wildlife Movement

Like the San Gabriel Mountains to the east, the Liebre-Sierra Pelona is a largely undeveloped, largely roadless mountain range bordering a megacity to the south. It may likewise be considered a “source” habitat for wide-ranging species such as mountain lion (Puma concolor) and golden eagle (Aquila chrysaetos) in the County. The freeways that border and cross the range, including Interstate 5 and S.R. 14, are thus of major concern for wildlife movement, and planning is underway to provide and improve wildlife crossing opportunities for these species in the form of underpasses and wildlife bridges.

Designation Criteria

The following table identifies which of the six existing SEA Selection Criteria and the proposed new SEA Selection Criterion are satisfied by the proposed SEA.

Criteria Summary of the Proposed Liebre-Sierra Pelona SEA

Lower Los Angeles River Proposed SEA (LAR)

General location and landform

Extending approximately six linear miles through the City of Long Beach, from Pacific Coast Highway north to Artesia Boulevard, and encompassing approximately 423 acres, the highly modified ecosystem of the lower Los Angeles River provides important habitat for a wide range of birds, and especially migratory shorebirds. The proposed SEA consists of the channel itself, administered by the Los Angeles County Flood Control District (LACFD), and associated restored wetlands of the Dominguez Gap (52 acres, restored by the LACFD in 2008) and DeForest Park (34 acres, restored by the City of Long Beach in 2018).

The proposed SEA is located within the Downey United States Geological Survey (USGS) 7.5' California Quadrangle.

Although not a formal SEA Selection Criterion, it is relevant that the Gabrieleño-Kizh/Tongva people regard the Los Angeles River—Paayme Paxaayt (“west river”) or Wenot (“the life-giver”)—as a centerpiece of trade, culture, and spirituality. Historically, at least 45 villages flourished along its length, including Ahwaanga near the river’s mouth. As such, formally recognizing the ecological significance of the lower Los Angeles River and associated wetlands through SEA designation would be consonant with and respectful of TEK.

Biological Resources

Vegetation and natural communities

The proposed designation of this area mainly reflects its unique value as a crucial stopover site for large numbers of shorebirds during fall migration, as summarized by Cooper (2006, p. 1): “The concrete-lined channel of the lower Los Angeles River in Long Beach supports one of the largest concentrations of shorebirds in southern California during fall migration. Each fall, the black-necked stilt (Himantopus mexicanus), western sandpiper (Calidris mauri), and least sandpiper (Calidris minutilla) occur in the thousands of individuals per day, and the American avocet (Recurvirostra americana) and long-billed dowitcher (Limnodromus scolopaceus) occur in the hundreds. Numbers peak from mid-August through late September, and eight systematic surveys between 9 August and 27 September 2000 yielded in excess of 14,000 birds on four of these counts. Despite the channel’s proximity to the coast, the species composition resembles that at other inland sites in the Southwest more closely than natural coastal wetlands in the region. Because of the channel’s constricted concrete borders, even slight rainfall can raise the water level in the channel, reducing the suitability of the habitat for shorebirds. This effect likely accounts for the area’s relatively light use by shorebirds outside the late summer and fall dry season.”

The Dominguez Gap Wetlands occupy two areas between the 405 freeway and Del Amo Boulevard: a 37-acre basin on the eastern side of the river channel and an 18-acre basin on the west side of the channel. The Deforest Wetlands occupy a basin 2.4 miles long on the eastern side of the river channel, from Del Amo Boulevard to Osgood Street. A review of eBird records show multiple summer records of least bitterns (Botarus exilis), Clark’s marsh wrens (Cistothorus palustris clarkae), and northern yellow warblers (Setophaga aestiva), suggesting localized nesting by these California Species of Special Concern in the Dominguez Gap Wetlands and possibly in the DeForest Wetlands. Other wetland-dependent nesting species include green heron (Butorides virescens) and tree swallow (Tachycineta bicolor).

The river channel itself does not support natural communities, but the Dominguez Gap Wetlands and DeForest Wetlands have been restored using a combination of riparian trees, including western sycamore (Platanus racemosa), Fremont cottonwood (Populus fremontii), and willows (Salix spp.), along with mulefat (Baccharis salicifolia) and emergent freshwater marsh vegetation, such as California bulrush (Schoenoplectus californicus) and broad-leaf cattail (Typha latifolia). Upland slopes of the basins have been restored with native coastal sage scrub species, such as California buckwheat (Eriogonum fasciculatum), coyote brush (Baccharis pilularis), and California sagebrush (Artemisia californica).

A small area of the lower channel through north Long Beach supports a rare seasonal alkali wetland community, with patches of southern tarplant (Centromadia parryi ssp. australis), along with wetsalts tiger beetles (Cicindelidia hemorrhagica) and other wetland indicators.

Wildlife movement

This channel and that of the San Gabriel River, several miles to the east, are the only geographic features connecting the southern coast of Los Angeles County to SEAs and other natural areas located 15 or more miles inland.

Designation Criteria

The following table identifies which of the six existing SEA Selection Criteria and the proposed new SEA Selection Criterion are satisfied by the proposed SEA.

Criteria Summary of the Proposed Lower Los Angeles River SEA

Pacoima Wash (PW) Proposed SEA

General location and landform

Lower Pacoima Wash extends for more than mile downstream of the USFS boundary as an un-channelized, boulder-filled coastal-slope alluvial wash, and is blocked by a large flood-control dam at Maclay St., just east of the 210 Freeway. One of the rarest habitats in the state, alluvial fan scrub is restricted to the remaining natural-floor drainages in the Los Angeles Basin and nearby lowlands, where the Basin meets the foothills of the Transverse and Peninsular ranges (e.g., San Gabriel River, Santa Ana River, San Jacinto River). The alluvial habitats of these sites stand in stark contrast with the surrounding upland habitats, which typically support chaparral and coastal sage scrub (or, more often, disturbed versions of these habitats, filled with non-native grasses and forbs) not associated with seasonal water flow.

The proposed SEA is located within the San Fernando United States Geological Survey (USGS) 7.5' California Quadrangles.

While the habitat at Pacoima Wash is less extensive and more disturbed than that at Big Tujunga Wash, the San Gabriel River, and a handful of other drainages in the eastern part of the County, it nonetheless supports numerous rare species (including many of those also found at Big Tujunga Wash), and thus represents an integral component of the original vegetation of the Los Angeles Basin.

Located at the northeastern edge of the densely urban San Fernando Valley, Pacoima Wash is bordered by El Cariso Community Regional Park to the west, and by dense residential and industrial development to the south; however, the northern connection to Angeles National Forest is still intact, and numerous large corridors into the ANF to the east (Lopez Canyon area) are also still open (including via “Lopez Canyon Sylmar Hiking Trail” and Lime Kiln Canyon (note: a different Limekiln Canyon is located on the southeastern slopes of the Santa Susana range, several miles to the west).

Biological Resources

Vegetation and natural communities

The alluvial fan scrub present at Pacoima Wash supports a highly diverse scrub community with California buckwheat (Eriogonum fasciculatum) particularly prevalent, and scattered laurel sumac (Malosma laurina). Notable plant species present include Tujunga bushmallow (Malacothamnus davidsonii), scalebroom (Lepidospartum squamatum, an indicator species for this habitat), and cane cholla (Cylindropuntia bernardina), all of which are highly restricted in the Los Angeles Basin. All (southern California) areas of alluvial fan scrub feature plants at their extreme physiological range, trying to survive in an extremely harsh environment (boulder-filled floodwaters, searing hot temperatures). Even riparian trees such as western sycamore adopt a distinctive growth form on these bajadas (alluvial fan slopes), stunted and often with multiple trunks.

Sensitive wildlife species known from the wash, or from nearby similar habitat, include San Diegan legless lizard (Anniella stebbinsi), Blainville’s horned lizard (Phrynosoma blainvillii), two-striped garter snake (Thamnophis hammondii) and coastal whiptail (Aspidoscelis tigris stejnegeri). Numerous rare species are known from upstream of USFS boundary, and may also occur in the lower wash, at least seasonally, including rare fishes, southwestern pond turtle (Actinemys pallida) and amphibians such as arroyo toad (Anaxyrus californicus). Surveys are urgently needed to document the presence (or absence) of these and other sensitive taxa.

Trask’s shoulderband is known from the area, and at least some of these records may pertain to the narrowly-endemic Pacoima shoulderband subspecies (Helminthoglypta traskii pacoimensis), which is known only from “Pacoima Canyon” and is believed to be “Critically Endangered”; the subspecies is known from specimens but has not been photographed in life.

Wildlife Movement

The natural habitats of Pacoima Wash essentially stop at the edge of urban development and are blocked from the rest of the San Fernando Valley by the massive 210 Freeway. However, a series of flood control channels convey water from the wash southwest to a large complex of settling ponds near Arleta, and then south into the Los Angeles River channel. Numerous pocket parks have been installed or are planned along Pacoima and Tujunga Wash, and the Los Angeles River, emphasizing its importance as an urban wildlife corridor. This includes not just large and mid-sized mammals, but also pollinators taking advantage of native plants (natural or planted), and smaller reptiles supported by strips of dirt (rather than concrete) along the channel right-of-way. These urban habitats are essentially “anchored” by the extensive alluvial scrub habitat of Pacoima Wash, which in turn is ecologically and literally connected to the extensive habitats of the San Gabriel Mountains SEA.

Designation Criteria

The following table identifies which of the six existing SEA Selection Criteria and the proposed new SEA Selection Criterion are satisfied by the proposed SEA.

Criteria Summary of the Proposed Pacoima Wash SEA

San Gabriel Mountains Proposed SEA (SGM)

General location and landform

The San Gabriel Mountains, together with the Liebre Mountain and the Sierra Pelona just to the northwest, are part of southern California’s Transverse Range, an east-west trending range of high, steep granitic mountains forming the northern edge of the Los Angeles Basin. Most of the land in these mountains is owned by the federal government and managed by the U.S. Forest Service as four separate Districts comprising Angeles National Forest. In addition, considerable areas of private lands are scattered throughout the forest, some including (rural) residential communities such as Green Valley and Kagel Canyon. The Forest boundary encompasses roughly 700,000 acres of Los Angeles County’s 3 million acres, stretching from the far northwestern corner near Gorman, southeast to Claremont at the San Bernardino County line (the San Gabriel Mountains extend several miles east into San Bernardino Co.). The Forest consists of two large, unconnected blocks of territory, split by S.R. 14 and the Santa Clara River. Despite covering just under 25% of the County’s total land area, ANF contains most of the County’s undeveloped open space, and nearly all its large roadless areas.

The San Gabriel Mountains contain some of the highest peaks in southern California, including Mount San Antonio (Mt. Baldy, aka Joat/Yoát “Snowy Mountain” to the Tongva, a local tribe), at 10,064’, Mt. Baden-Powell (9.339’), and a dozen other peaks over 8,000’.

A massive range containing and straddling multiple biomes (including the Mojave Desert to the north, and the coastal Los Angeles Basin to the south), the San Gabriel Mountains supported a rich Indigenous history, with native peoples taking full advantage of the available game and abundant fruits such as acorns (Quercus spp.), chia (Salvia columbariae), and manzanita (Arctostaphylos spp.). Trading routes and footpaths for seasonal movements were extensive, connecting different portions of the mountains, and villages, with the lowlands to the north and south.

Biological Resources

Vegetation and natural communities

It is difficult to summarize the vegetation of so diverse an area as the San Gabriel Mountains. Nearly all the habitats of mainland southern California may be found within Angeles National Forest, with the exception of desert-floor vegetation (e.g., creosote bush scrub, alkali sink scrub) and coastal scrub vegetation at immediate coastal sites such as the Palos Verdes Peninsula. Microhabitats abound—small sag ponds forming marshy meadows are located along the northern base of the range (natural wetlands along the coastal slope have largely been replaced by urbanization). Several major watersheds originate in the San Gabriel Mountains, producing the major waterways of southern California (including Santa Clara River, Los Angeles River, San Gabriel River, and in the north, Big Rock and Little Rock creeks).

As of 2008—i.e., prior to long-term drought that began in c. 2010, and a series of devastating fires including the Station Fire (2009, 169,000+ acres) and the Bobcat Fire (2020, 115,000+ acres)—the vegetation present in the Angeles National Forest (including the bulk of the Liebre-Sierra Pelona and the San Gabriel Mountains portions) was estimated at more than 50% chaparral, with 23% conifer woodland and 9% “hardwoods” (largely oak woodland) (Schaaf et al. 2008). Since 2020, however, the amount of coniferous forest has plummeted, and oak woodland is similarly reduced, due to fire and drought. Today, the pockets of high-elevation coniferous forest and meadow habitat, rich in rare species, are truly imperiled, both by forces easily managed (e.g., human intrusion and trampling) and largely out of human control (long-term drought and climate change).

In a 1998 analysis (updated with newer taxonomy in 2005), Angeles National Forest was thought to support 23 “Forest Sensitive Plant Species”, most entirely restricted in the County to the San Gabriel Mountains, and dozens of sensitive wildlife species. The San Gabriel Mountains are known to support 24 endemic or near-endemic plant taxa, 15 of which are only found here. Many of these are listed as Threatened or Endangered by state or federal agencies or California Native Plant Society, including Greata’s aster (Symphyotrichum greatae), San Gabriel manzanita (Arctostaphylos glandulosa ssp. gabrielensis), Palmer’s mariposa lily (Calochortus palmeri var. palmeri), San Gabriel linanthus (Linanthus concinnus), wooly mountain-parsley (Oreonana vestita), Mount Gleason paintbrush (Castilleja gleasoni), Bear Valley woolypod (Astragalus leucolobus), San Antonio milkvetch (Astragalus lentiginosus var. antonius), Ewan’s woodbeauty (Drymocallis cuneifolia var. ewanii), southern alpine buckwheat (Eriogonum kennedyi var. alpigenum), Johnston’s buckwheat (E. microtheca var. johnstonii), San Gabriel Mountains monardella (Monardella australis ssp. gabrielensis), Brown’s Flat monardella (M. breweri ssp. glandulifera), Abram’s oxytheca (Acanthoscyphus parishii var. abramsii), Rock Creek broomrape (Aphyllon validum ssp. validum), lemon lily (Lilium parryi), gray-leaved violet (Viola pinetorum ssp. grisea), and Peirson’s lupine (Lupinus peirsonii). No fewer than 30 rare, but not Threatened/Endangered, plant species are known from the San Gabriel Mountains, many occurring nowhere else in the County, including Jepson’s bedstraw (Galium jepsonii), urn-flowered alumroot (Heuchera caespitosa), California adder’s tongue (Ophioglossum californicum) and silky lupine (Lupinus elatus).

Examples of sensitive wildlife taxa of the San Gabriel Mountains not found anywhere else in the County include the amphibians mountain yellow-legged frog (Rana muscosa) and San Gabriel Mountains slender salamander (Batrachoseps gabrieli); birds such as nesting bald eagle (Haliaeetus leucocephalus), black swift (Cypseloides niger), purple martin (Progne subis); the rare fish Santa Ana speckled dace (Rhinichthys gabrielino) and Santa Ana sucker (Catostomus santaanae) are found in the Big Tujunga watershed and locally elsewhere; San Gabriel elfin (Callophrys mossii hidakupa; a butterfly) and Nelson’s (or “desert”) bighorn sheep (Ovis canadensis nelsoni) are restricted to rocky habitat in the eastern portion of the range. Several other sensitive species occur primarily in the San Gabriel Mountains in the County, with small, often relict populations in the lower Liebre-Sierra Pelona range (e.g., California spotted owl, Strix occidentalis occidentalis).

Dozens of wildlife species that aren’t recognized as sensitive at the state level are restricted in the County to the San Gabriels, with many occurring in the County only in these mountains. These include birds such as common nighthawk (Chordeiles minor), flammulated owl (Psiloscops flammeolus), gray flycatcher (Empidonax wrightii), hermit thrush (Catharus guttatus), Lincoln’s sparrow (Melospiza lincolnii), MacGillivray’s warbler (Geothlypis tolmei), Nashville warbler (Leiothlypis ruficapilla), plumbeous vireo (Vireo plumbeus), Williamson’s sapsucker (Sphyrapicus thyroideus) and Wilson’s warbler (Cardellina pusilla).

Tragically, a localized subspecies of greenish blue, the San Gabriel Mountains blue butterfly (Plebejus saepiolus aureolus) was rendered extinct (last seen 1980s) after a water diversion project near Big Pine destroyed its wet meadow habitat. The nearest populations of greenish blue persist in the Piute, San Bernardino and San Jacinto mountains (iNaturalist), all of which are separate subspecies than that which formerly occupied the San Gabriel Mountains.

Wildlife Movement

As a massive, largely undeveloped, largely roadless mountain range bordering a megacity to the south, and surrounded by rapidly urbanizing land, the importance of the San Gabriel Mountains to wildlife connectivity throughout the County (and beyond) cannot be overstated. The San Gabriels may be considered a “source” habitat for wide-ranging species such as mountain lion (Puma concolor) and golden eagle (Aquila chrysaetos) in the County, and presumably “supply” many of the individuals dispersing to more urban open space areas such as the Verdugo Mountains and Santa Susana Mountains. Poorly known and rarely seen mammals such as southern California ringtail (Bassariscus astutus octavus) and western spotted skunk (Spilogale gracilis) likewise would be expected to maintain source populations not in isolated urban open spaces in the Los Angeles Basin, but in the rugged mountains to the north. The freeways that border and cross the San Gabriel Mountains are thus of major concern for wildlife movement, and planning is underway to provide and improve wildlife crossing opportunities for these species in the form of underpasses and wildlife bridges.

Designation Criteria

The following table identifies which of the six existing SEA Selection Criteria and the proposed new SEA Selection Criterion are satisfied by the proposed SEA.

Criteria Summary of the Proposed Angeles National Forest/San Gabriel Mountains SEA

San Rafael Hills Proposed SEA (SR)

General location and landform

The San Rafael Hills are a low-elevation transverse range located in central Los Angeles County, southeast of the Verdugo Mountains and west of the Arroyo Seco. The neighborhoods of Eagle Rock and Glassell Park lie to the south, and the urbanized San Fernando Valley to the west. Elevations range from approximately 720 to 1,889 feet above mean sea level. Two major canyons, Scholl and Sycamore, run east to west. Soils include multiple calcareous types. The San Rafael Hills retain substantial areas of native vegetation, steep rugged topography, incised canyons, and natural drainage systems. Although they are sometimes referred to as an island of open space surrounded by development, tenuous connections remain to the Altadena Foothills and Arroyos SEA (across the 210 freeway through Hahamonga Watershed Park), and to the Verdugo Hills SEA (across North Verdugo Road). The hills cover approximately 7,040 acres, 3,413 of which are recommended for designation as a new SEA. Most of the remaining acreage is low-density housing and other land uses suitable for designation as connectivity overlay.

The San Rafael Hills occur within portions of the United States Geological Survey (USGS) 7.5’ quadrangles for Pasadena, Glendale, and Burbank.

Although not a formal SEA Selection Criterion, it is relevant that the San Rafael Hills are part of the ancestral homelands of the Gabrieleño-Kizh/Tongva people, with the historical village of Toviscangna located approximately five miles southeast of the hills near present-day Mission San Gabriel Arcangel. The San Rafael Hills were important as a natural resource area, providing materials that included willow for houses. As such, formally recognizing the ecological significance of the San Rafael Hills through SEA designation would be consonant with and respectful of TEK.

Biological Resources

The San Rafael Hills support a mosaic of native plant communities characteristic of foothill environments in Los Angeles County, including expanses of chaparral, coastal sage scrub, coast live oak woodland, and localized riparian and oak-sycamore woodland along canyon bottoms and ephemeral drainages. North-facing slopes and shaded ravines tend to support denser chaparral and woodland assemblages, while south- and west-facing slopes are characterized by more open coastal sage scrub and drought-tolerant chaparral species.

Natural communities described for this area include various forms of chaparral, coastal sage scrub, oak woodland, walnut woodland, California sycamore woodland, and mixed riparian woodland (Soza et al. 2013). Sensitive and noteworthy plant species recorded the San Rafael Hills include one plant with a California Rare Plant Rank of 1B.2 (plants rare or endangered in California and elsewhere) and several watch-list plants of limited distribution: chaparral nolina (Nolina cismontana), Plummer’s mariposa lily (Calochortus plummerae), fragrant pitcher-sage (Lepechinia fragrans), ocellated Humboldt lily (Lilium humboldtii ssp. ocellatum), southern California black walnut (Juglans californica), San Gabriel oak (Quercus durata var. gabrielensis) and Engelmann oak (Q. engelmannii). The hills are near the western edge of the range of Engelmann oak. A distinctive form of summer lupine (Lupinus formosus) is also known from here[2].

Sensitive and noteworthy wildlife species known from the San Rafael Hills include one Candidate for State listing, Crotch’s bumble bee (Bombus crotchii), and several California Species of Special Concern: coast range newt (Taricha torosa), Blainville’s horned lizard (Phrynosoma blainvillii), coastal whiptail (Aspidoscelis tigris stejnegeri), two-striped garter snake (Thamnophis hammondii), and northern yellow warbler (Setophaga aestiva). Also present is Trask shoulderband snail (Helminthoglypta traskii), which has a NatureServe Rank of S2 (Imperiled, at high risk of extirpation in the state due to restricted range, few populations or occurrences, steep declines, severe threats, or other factors).

The San Rafael Hills represent the southernmost extent of the Transverse Range flora and fauna into the Los Angeles Basin; as such, they support species like Merriam’s chipmunk, black bear, and others that do not (regularly) occur farther south. Mule deer also cannot penetrate the Basin’s urban matrix farther south than the San Rafael Hills. For this reason, they are considered to be an important extension of such habitat, providing a stepping-stone from the Basin into the mountains.

Wildlife movement

The San Rafael Hills are situated south of the San Gabriel Mountains, east of the Verdugo Mountains to the west, and the Arroyo Seco to the east, and thus may function as an important linkage for these expansive open spaces. Obstacles to terrestrial movement through the San Rafael Hills include State Route 2, which runs north/south through the eastern part of the range, and the 210 freeway, which separates the San Rafael Hills from the San Gabriel Mountains. They are also the first large open space block of habitat providing a source for dispersal lower into the Basin (e.g., via the Arroyo Seco), and vice-versa. Efforts to identify and protect the remaining connections across these major barriers are warranted.

Designation Criteria

The following table indicates which of the existing SEA Selection Criteria and the one proposed new SEA Selection Criterion are satisfied by the proposed SEA.

Criteria Summary of the Proposed San Rafael Hills SEA

Sepulveda Basin Proposed SEA (SB)

General location and landform

The Sepulveda Basin comprises more than 2,000 acres of mostly undeveloped land including and alongside the Los Angeles River in the middle of the San Fernando Valley. It occupies the confluences of several tributaries of the Los Angeles River, Bull Creek, Encino Creek and Haskell Creek, and supports a mix of various bottomland vegetation communities largely lost on the floor of the Basin. It is isolated from the Santa Monica Mountains by a major freeway and residential development; however, Encino Creek provides at least hydrological connection between the Basin and that range. A variety of ownership and management overlays cover Sepulveda Basin, including US Army Corps of Engineers (owns most of the land) and the city of Los Angeles (manages most of the land, with the exception of the “South Reserve” south of Burbank Blvd.).

The proposed SEA is located within the Canoga Park and Van Nuys United States Geological Survey (USGS) 7.5' California Quadrangles.

Biological Resources

Vegetation and natural communities

The Sepulveda Basin, one of a handful of large remaining open space areas on the floor of the Los Angeles Basin, is a mixed-use recreational area with considerable natural habitats, including:

·        A 1-mile natural-floor stretch of the Los Angeles River, with native willow-dominated riparian vegetation;

·        “Bull Creek Restoration Area”, completed in 2009, located just north and west of Lake Balboa;

·        Several marsh-lined ponds located in the designated “wildlife area”, as well as on the Woodley Lakes Golf Course;

·        Multiple active colonial waterbird rookeries;

·        Natural riparian scrub vegetation with scattered Fremont cottonwood and other trees in the “South Reserve” area south of Burbank Blvd.;

·        A large constructed (cement-lined) reservoir (Lake Balboa) that supports waterbirds in winter.

Out of the 2,000+ acres within the Sepulveda Basin, 285 acres consisting of Bull Creek, the Los Angeles River, and Haskell Creek with its associated wildlife lake and adjacent undeveloped uplands, are proposed for SEA designation. While physically isolated from other open space areas of the County, its location along the Los Angeles River makes it a crucial component of future restoration efforts (The River Project 2022).

The Los Angeles River channel itself and associated habitats support Fremont cottonwood (Populus fremontii), and willows (Salix spp.), along with mulefat (Baccharis salicifolia) and emergent freshwater marsh vegetation, such as California bulrush (Schoenoplectus californicus) and broad-leaf cattail (Typha latifolia). This habitat supports numerous wildlife species found only in freshwater marsh, including rails (family Rallidae) and dragonflies/damselflies (order Odonata). Sanford’s arrowhead (Sagittaria sanfordii), a CRPR 1B.2 plant, was recently discovered along the Los Angeles River channel, and numerous wetland plant species occur within the basin (Cooper et al. 2022). Since formal botanical surveys have never been conducted here, more may await discovery.

Sensitive and noteworthy wildlife species confirmed as nesting at Sepulveda Basin include the Endangered least Bell’s vireo (Vireo bellii pusillis) and multiple California Species of Special Concern, including the least bittern (Botarus exilis), Clark’s marsh wren (Cistothorus palustris clarkae), yellow-breasted chat (Icteria virens) and northern yellow warbler (Setophaga aestiva).

A large rookery consisting mainly of double-crested cormorant (Nannopterum auritum) and great blue heron (Ardea herodias) is located on a small island within the Wildlife Area, and a smaller great blue heron rookery is located adjacent to the Los Angeles River. Additional rookeries of herons and egrets have been found scattered throughout the Basin, appearing unpredictably from year to year.

The Los Angeles River includes an unchannelized portion, with natural sand/silt banks, just south of Woodley Golf Course. This fragment represents one of the few remaining large examples of a natural riparian zone in the coastal lowlands. Upland slopes of the Los Angeles River levee have been restored with native coastal sage scrub species, such as California buckwheat (Eriogonum fasciculatum), coyote brush (Baccharis pilularis), and California sagebrush (Artemisia californica). American kestrel, an open country species now rare year round, has bred in the Basin at least once in the past 10 years. In grassland areas, both burrowing owl (Athene cunicularia) and loggerhead shrike (Lanius ludovicianus) are regular in fall and winter, one of the few locales in urban Los Angeles where they still occur.

Wildlife movement

The Los Angeles River channel represents a major urban wildlife corridor through the urban Los Angeles Basin.

Designation Criteria

The following table identifies which of the six existing SEA Selection Criteria and the proposed new SEA Selection Criterion are satisfied by the proposed SEA.

Criteria Summary of the Proposed Sepulveda Basin SEA