Sheep Mountain

The Sheep Mountain Inventoried Roadless Area covers 21,098 acres of high San Gabriel Mountains terrain on the San Gabriel Mountains National Monument Ranger District of Angeles National Forest. The country rises from the Iron Fork–San Gabriel River canyon over the Devils Backbone and Blue Ridge to Mount San Antonio (Mount Baldy), Mount Baden-Powell, Throop Peak, Mount Burnham, Mount Harwood, Mount Hawkins, South Mount Hawkins, Wright Mountain, and Rattlesnake Peak. Vincent Gap and Inspiration Point mark the high passes; San Antonio Canyon, Bear Canyon, Cattle Canyon, Shoemaker Canyon, Bichota Canyon, Cloudburst Canyon, and Sheep Canyon cut the slopes. The area drains the Iron Fork–San Gabriel River headwaters along with Cedar Creek, Iron Fork, Big Rock Creek, South Fork Big Rock Creek, and Big Butch Wash. Springs at Lamel Spring, White Fir Spring, Fallen Leaf Spring, Lily Spring, and Forked Spruce Spring deliver groundwater year-round; San Antonio Falls drops off Mount San Antonio's north face.

Forest cover changes sharply with elevation. The lower slopes carry California Chaparral, California Mountain Chaparral, and Mojave Desert Chaparral with common chamise (Adenostoma fasciculatum), bigberry manzanita (Arctostaphylos glauca), buckbrush (Ceanothus cuneatus), hoaryleaf ceanothus (Ceanothus crassifolius), and chaparral whitethorn (Ceanothus leucodermis). California Coastal Live Oak Woodland and California Foothill Mixed Oak Woodland hold California live oak (Quercus agrifolia) and California black oak (Quercus kelloggii) along the lower canyon walls. California Mixed Conifer Forest takes over upslope with sugar pine (Pinus lambertiana), white fir (Abies concolor), Jeffrey pine (Pinus jeffreyi), incense cedar (Calocedrus decurrens), and the Southern California endemic big-cone Douglas-fir (Pseudotsuga macrocarpa). On the desert face, Great Basin Pinyon-Juniper Woodland mixes single-leaf piñon (Pinus monophylla) with Western Joshua tree (Yucca brevifolia) at the lowest elevations. The high crest holds krummholz limber pine (Pinus flexilis) along the Blue Ridge and Devils Backbone, with lodgepole pine (Pinus contorta) on the windier ridges. The IUCN-vulnerable Plummer's mariposa lily (Calochortus plummerae) and Burlew's onion (Allium burlewii) hold in specific habitats; lemon lily (Lilium parryi) grows at the seep margins.

American black bear (Ursus americanus), mule deer (Odocoileus hemionus), mountain lion (Puma concolor), bobcat (Lynx rufus), gray fox (Urocyon cinereoargenteus), and bighorn sheep (Ovis canadensis) range the slopes — the bighorn give the area its name. Lodgepole chipmunk (Neotamias speciosus) and Merriam's chipmunk (Neotamias merriami) hold in the higher conifer. The critically imperiled Transverse Range Shoulderband snail (Helminthoglypta petricola), a San Gabriel endemic, lives in moist chaparral leaf litter. The San Gabriel Mountains Slender Salamander (Batrachoseps gabrieli), a near-threatened range endemic, lives under bark and duff in the canyons. California treefrog (Pseudacris cadaverina) and California newt (Taricha torosa) live along the cool reaches of Cattle Canyon and the Iron Fork. In the canopy, Clark's nutcracker (Nucifraga columbiana), pygmy nuthatch (Sitta pygmaea), mountain chickadee (Poecile gambeli), Williamson's sapsucker (Sphyrapicus thyroideus), and the near-threatened olive-sided flycatcher (Contopus cooperi) work the conifer crest. Lower in the oak belt, acorn woodpecker (Melanerpes formicivorus), Nuttall's woodpecker (Dryobates nuttallii), oak titmouse (Baeolophus inornatus), and California thrasher (Toxostoma redivivum) hold. Rainbow trout (Oncorhynchus mykiss) hold in the cold reaches of the Iron Fork and East Fork tributaries. Portions of this area fall within the potential range of several federally listed species; see the Conservation section for details.

A traveler crossing the Sheep Mountain country climbs from chamise chaparral and live oak woodland up through Coulter pine and big-cone Douglas-fir into the Jeffrey and lodgepole pines of the high ridges. The Devils Backbone trail runs along the crest from Manker Flats to Mount San Antonio. Beyond Vincent Gap, Mount Baden-Powell and Throop Peak rise above the limber pine; the Pacific Crest Trail threads the high ridges. Down in San Antonio Canyon, water drops over San Antonio Falls into the Iron Fork drainage.

The Sheep Mountain Inventoried Roadless Area, a 21,098-acre tract within the San Gabriel Mountains National Monument Ranger District of Angeles National Forest, lies at the headwaters of the Iron Fork–San Gabriel River in the eastern San Gabriel Mountains, Los Angeles and San Bernardino counties. Its history reflects long Tongva (Gabrielino) and Serrano presence in these uplands, mission-era and gold-rush disruption, and the federal forest reserves that grew into Angeles National Forest.

Native occupation of the San Gabriel uplands reaches back to early Holocene times: "Radiocarbon dates of 7675 and 7600 years Before Present (BP)" — taken from a cooking feature in one of the northern drainages of the San Gabriel Mountains — "are the oldest known from the central Transverse Ranges" [1]. Material culture from this period shows "extensive use of grinding implements to process small seeds, supplemented by hunting activities" and "numerous cogged stones... indicating ceremonial activities" [1]. By the Late Period (800 BP to AD 1769), "village provinces, composed of politically and economically-aligned villages, may have existed," and "greater regional interaction is marked by an increase in non-local materials, indicative of widespread interregional trade networks" [1]. The Tongva (Gabrielino) held the basin and lower mountains; the Serrano held the higher eastern San Gabriels and the desert face beyond. "The first reported European contact for the area of what is now the Angeles National Forest was in 1769, when the expedition of Gaspar de Portola traveled through the neighboring valleys" [1]. "The construction of the missions of San Gabriel Archangel (1771) and San Fernando Rey de España (1797) cemented Spanish presence in the region," and "by 1800, local traditional Tribal cultural lifestyles had largely disappeared due to devastating European influences, including diseases and incorporation into the Mission System" [1].

Industrial use of the San Gabriels began in the early nineteenth century. "The first documented instance of timber activity in the local mountains was in 1819 when Joseph Chapman cut down timber in Millard Canyon... for use in the construction of the Plaza Church" of Los Angeles [1]. With Mexican Independence in 1821 the region passed under Mexican control, and seasonal grazing on the highlands followed. "Gold was discovered in Placerita Canyon in 1842. This was the first authenticated discovery of gold in California. It started California's 'first' Gold Rush" [1]. After the 1848 Gold Rush at Sutter's Mill and U.S. annexation, "miners poured into the mountains primarily following original and modified American Indian trails. Large placer and lode mining operations were established in the San Gabriel Mountains" [1]; the East Fork of the San Gabriel River, adjacent to the Sheep Mountain area, was a major gold-mining district. "Many of the ventures were inactive by 1896," and serious mining "largely ended by the late 1930s" [1]. "Don Benito Wilson, in 1864, built a road into the forest to harvest wood for fence posts, wine barrels, pickets and shingles" [1].

Federal protection came in 1892. "On December 20, 1892, the San Gabriel Timberland Reserve was created by President Harrison" in response to flood damage from fire-denuded slopes [2]. "In 1905, the reserves were transferred from the Department of the Interior to the Department of Agriculture and renamed national forests in 1907"; "in 1908, the name was changed to Angeles National Forest" [1]. In 1926 the eastern area was divided and San Bernardino National Forest was recreated. Today the Sheep Mountain area lies within the San Gabriel Mountains National Monument (proclaimed in 2014) and is protected under the 2001 Roadless Area Conservation Rule.

Vital Resources Protected

• Cold-Water Headwater Integrity: The 21,098-acre roadless condition keeps the Iron Fork–San Gabriel River headwaters — along with Cedar Creek, Iron Fork, Big Rock Creek, and South Fork Big Rock Creek — free of ditch-and-fill drainage networks. Intact streambanks and a closed riparian canopy preserve the cold reaches that the threatened Santa Ana sucker (Catostomus santaanae) and the proposed-threatened Santa Ana speckled dace (Rhinichthys gabrielino) require, along with habitat for arroyo toad (Anaxyrus californicus) and southern mountain yellow-legged frog (Rana muscosa). Lamel Spring, White Fir Spring, Fallen Leaf Spring, Lily Spring, and Forked Spruce Spring continue to deliver groundwater year-round.

• Climate Refugia in High-Elevation Conifer Forest: The roadless state preserves an unbroken corridor of California Mixed Conifer Forest, Sierra Nevada Jeffrey Pine Forest, and high-elevation limber pine (Pinus flexilis) stands from San Antonio Canyon up to Mount San Antonio, Mount Baden-Powell, Throop Peak, and the Devils Backbone. The Southern California endemic big-cone Douglas-fir (Pseudotsuga macrocarpa) and the IUCN-vulnerable lemon lily (Lilium parryi) persist in narrow microclimates that intact canopy and seep hydrology protect. These high-elevation islands serve as climate refugia for mountain-adapted species as lower-elevation habitats warm and dry.

• Bighorn Sheep and Endemic Invertebrate Habitat: Continuous chaparral, oak woodland, and conifer cover from the Iron Fork canyon up to the Devils Backbone supports the bighorn sheep (Ovis canadensis) population that gives the area its name. The critically imperiled Transverse Range Shoulderband snail (Helminthoglypta petricola), a San Gabriel endemic, lives in moist chaparral leaf litter; the San Gabriel Mountains Slender Salamander (Batrachoseps gabrieli), a range-restricted near-threatened species, lives in canyon duff. Roadless conditions preserve the leaf-litter depth, humidity, and microhabitat continuity these species require.

Potential Effects of Road Construction

• Sedimentation of Native Fish Streams: Cut slopes and fill embankments along new road grades shed fine sediment downhill with every storm, embedding gravel beds in the Iron Fork, Cedar Creek, and Big Rock Creek with silt. That sediment suffocates aquatic insect communities and seals the interstitial spaces that Santa Ana sucker, Santa Ana speckled dace, and arroyo toad require for breeding and rearing. Post-fire and post-storm slope failures already deliver heavy sediment loads to the San Gabriel watershed, and new road erosion compounds existing damage to the downstream supply that serves Los Angeles County.

• Fragmentation of Bighorn and Endemic-Species Habitat: Road construction across the upper slopes severs the continuous corridor that bighorn sheep use to move between ridges and water sources. Linear clearings change microclimate at the moisture margins where big-cone Douglas-fir, lemon lily, and the endemic shoulderband snail persist; they expose interior species to predation and disturbance; and they open disturbed corridors for invasive plants — Spanish broom (Spartium junceum), cheatgrass (Bromus tectorum), tree-of-heaven (Ailanthus altissima), tree tobacco (Nicotiana glauca), and yellow star-thistle — to move into the chaparral and conifer country.

• Hydrological Disruption of Springs and Seeps: Road cuts, drainage ditches, and culverts intercept the subsurface flow that feeds Lamel Spring, White Fir Spring, Fallen Leaf Spring, Lily Spring, and Forked Spruce Spring. Drainage shifts reduce the baseflow that sustains the cold-water reaches of the Iron Fork and dry out the seep margins where lemon lily and tall white bog orchid grow. Reestablishing spring hydrology after road-driven incision is a slow, often incomplete process; for the narrow-range Transverse Range Shoulderband snail, loss of leaf-litter humidity along a road corridor can be terminal.

The 21,098-acre Sheep Mountain Inventoried Roadless Area lies in the eastern San Gabriel Mountains of Angeles National Forest, on the San Gabriel Mountains National Monument Ranger District. The country includes the high crest from Mount San Antonio (Mount Baldy) east across the Devils Backbone and Blue Ridge to Mount Baden-Powell, Throop Peak, and Mount Hawkins. The Pacific Crest Trail runs along the ridgeline; ten trailheads serve the area — Islip Wawona, San Antonio Falls, Vincent's Gulch, East Fork / Heaton Flats, Cabin Flat, Windy Gap, Islip, Inspiration Point, Upper Bear Creek, and Icehouse.

Hiking, stock travel, and limited biking. The Pacific Crest Trail through this stretch is split into named segments — PCT Dawson Saddle (332000.13), 23.2 miles of horse-use route, is the longest line; PCT Wright Mountain to Inspiration Point (332000.16), 6.7 miles; PCT Baden-Powell (332000.14), 6.2 miles, hiker; PCT Section 2 (2000.02), 6.1 miles, hiker/horse/bike; and PCT Grassy Hollow (332000.15), 4.4 miles, hiker. The Mt. Baldy Trail (237W12), 5.7 miles, climbs from Manker Flat to the summit — on an asphalt surface. Other key routes include the Bichota Canyon Trail (239W17), 5.5 miles; High Desert NRT/Manzanita (339W07), 5.4 miles, horse; Fish Fork (338W10), 4.8 miles, horse; Mine Gulch (338W03), 4.2 miles, horse; South Hawkins Trail (233N07), 4.2 miles; Heaton Flats Trail (238W16), 3.9 miles; the North Devils Backbone (337W05.2), 3.7 miles; East Fork Trail (238W13), 3.7 miles; Graveyard Canyon (238W12), 2.7 miles; the Devils Backbone Trail (237W05), 2.7 miles to Mount San Antonio; the Baldy Bowl Trail (237W02), 2.6 miles; Prairie Fork (338W07), 2.4 miles; Blue Ridge (338W28), 2.1 miles; and Hawkins Ridge (239W28), 2.1 miles. Most routes are hiker- or horse-use; PCT Section 2 is the documented hiker/horse/bike segment.

Camping and base access. Eleven developed campgrounds serve the area: Jackson Flat Group, Crystal Lake Campground, Blue Ridge, Coldbrook, Little Jimmy, Manker Flat, Lake, Lupine, Appletree, Guffy, and Peavine. Manker Flat is the standard base for Mount San Antonio climbs; Blue Ridge and Guffy are common PCT trail-camp options. Dispersed backcountry camping is the rule once travelers leave road-accessible sites.

Fishing. The cold reaches of the Iron Fork–San Gabriel River, Cedar Creek, and Big Rock Creek carry rainbow trout (Oncorhynchus mykiss). The native Santa Ana sucker and Santa Ana speckled dace are documented in the broader San Gabriel watershed; both are listed and not legally targeted. The East Fork of the San Gabriel River, adjacent to the area, is a long-standing recreational gold-panning destination as well as a trout fishery — a California fishing license and current California Department of Fish and Wildlife regulations apply.

Hunting. Big-game habitat includes mule deer (Odocoileus hemionus), American black bear (Ursus americanus), and mountain lion (Puma concolor) under California tag and quota rules. Bighorn sheep (Ovis canadensis) range the high country but are not legally hunted in this area. Mountain quail (Oreortyx pictus), California quail (Callipepla californica), band-tailed pigeon (Patagioenas fasciata), and mourning dove (Zenaida macroura) occupy oak woodland and chaparral edges. Verify current hunting regulations and area restrictions with CDFW; portions of the San Gabriel Mountains National Monument carry specific use rules.

Birding and photography. Twenty-four eBird hotspots near the area frame what birders can expect, with Grassy Hollow (139 species, 1,811 checklists) the most active, followed by San Gabriel Canyon Road below East Fork (129 species), Blue Ridge Road (124), Barrett-Stoddard Truck Trail (123), and Blue Ridge Campground (114). The Throop Peak/Dawson Saddle Trail (110 species) and Crystal Lake Recreation Area (107) sit at the area's edges. Inside the country, Clark's nutcracker (Nucifraga columbiana), pygmy nuthatch (Sitta pygmaea), mountain chickadee (Poecile gambeli), Williamson's sapsucker (Sphyrapicus thyroideus), white-headed woodpecker (Leuconotopicus albolarvatus), Lewis's woodpecker (Melanerpes lewis), and California condor (Gymnogyps californianus) overhead are reliable subjects. Mount San Antonio's north face, San Antonio Falls, the limber pine ridges near Mount Baden-Powell and Throop Peak, and the Devils Backbone are productive landscape photography sites.

Why the roadless condition matters here. The Pacific Crest Trail experience, the high-elevation backcountry climbs to Mount San Antonio and Mount Baden-Powell, the cold-water trout streams of the Iron Fork, the bighorn sheep range, and the limber pine ridgelines all depend on the absence of new road construction across these slopes. Road building would fragment the bighorn movement corridor and replace foot-and-stock travel on the most heavily used wilderness ridges in Southern California with mechanized access these experiences cannot survive.