Bighorn Mountain

Bighorn Mountain

Mt Baldy and Bighorn Peak in the San Gabriel Mountains near Ontario and Los Angeles, California | trekandshoot

🏔️ Overview

Bighorn Mountain is a high, rugged summit in Southern California’s San Bernardino Mountains, rising immediately southeast of San Gorgonio Mountain. Although overshadowed by its famous neighbor, Bighorn reaches approximately 11,006 feet, making it one of the highest summits in Southern California.

The mountain stands within the San Gorgonio Wilderness, where forested valleys, exposed ridges, and rocky alpine terrain create a landscape far removed from the surrounding cities and desert communities. Unlike San Gorgonio’s well-traveled summit trails, Bighorn Mountain requires at least some off-trail travel, giving the peak a quieter and more adventurous character.

Bighorn Mountain should not be confused with Bighorn Peak in the San Gabriel Mountains, the separate Bighorn Mountain Wilderness near the Mojave Desert, or the Bighorn Mountains of Wyoming and Montana. This profile focuses specifically on the high summit southeast of San Gorgonio Mountain in San Bernardino County, California.

⚡ Fast Facts

Fact	Details
Continent	North America
Country	United States
State/Province	California
County/Region	San Bernardino County
Mountain Range	San Bernardino Mountains
Parent Peak	San Gorgonio Mountain
Elevation	Approximately 11,006 feet / 3,355 meters
Traditional Listed Elevation	10,997 feet / 3,352 meters
Prominence	Approximately 399 feet / 122 meters
Isolation	Approximately 0.36–0.37 mile / 0.58–0.60 kilometer
Nearest Higher Neighbor (NHN)	San Gorgonio Mountain
Coordinates	Approximately 34.09056° N, 116.81871° W
Larger Mountain System	Transverse Ranges
Protected Area	San Gorgonio Wilderness
National Forest	San Bernardino National Forest
Common Approaches	Vivian Creek, South Fork, and Fish Creek when accessible
Typical Hiking Difficulty	Strenuous; established trails combined with cross-country travel
Wilderness Permit	Required for day hikes and overnight trips
Sierra Club Peak List	Hundred Peaks Section
USGS Quadrangle	San Gorgonio Mountain

📍 Location

Bighorn Mountain occupies the southeastern portion of the San Bernardino Mountains, a major component of Southern California’s east-west-trending Transverse Ranges.

The summit lies southeast of San Gorgonio Mountain and above the upper reaches of Mill Creek Canyon. Forest Falls, a small mountain community reached from California State Route 38, provides access to the popular Vivian Creek Trailhead southwest of the peak.

Bighorn forms part of the remarkably high terrain surrounding San Gorgonio, where several closely spaced summits rise above 10,000 feet. From lower elevations, the mountain can be difficult to distinguish because its ridge blends into the larger San Gorgonio massif. Its individual form becomes much clearer from nearby high-country trails and from the basin separating it from San Gorgonio.

A flat, often dry depression known as The Tarn lies between the mountains. This feature serves as an important navigation landmark for hikers approaching Bighorn from San Gorgonio or the Sky High Trail.

Despite the similar names, Bighorn Mountain is not located within the separate Bighorn Mountain Wilderness farther east. That protected area occupies lower, more desert-influenced terrain near the eastern foothills of the San Bernardino Mountains.

📏 Elevation & Prominence

Bighorn Mountain’s elevation varies among published references because different organizations use different maps, surveys, and elevation datasets.

Older hiking references, including the Sierra Club’s Hundred Peaks Section, commonly list the summit at 10,997 feet. A historical wilderness map published in 1971 gave an elevation of 11,005 feet. More recent Peakbagger data identifies the mountain at approximately 11,006.1 feet, or 3,354.7 meters.

For practical purposes, Bighorn is best described as an approximately 11,006-foot mountain, while acknowledging that hikers may encounter the older 10,997-foot figure in established guidebooks and online descriptions.

Its topographic prominence is approximately 398.6 feet, or 121.5 meters. This means the summit rises nearly 400 feet above the highest connecting saddle leading toward higher terrain on the San Gorgonio massif.

Bighorn’s isolation is comparatively modest, at approximately 0.36 to 0.37 mile. The nearest higher terrain belongs to San Gorgonio Mountain, which is both Bighorn’s parent peak and its nearest higher neighbor.

Although Bighorn does not have the enormous prominence of San Gorgonio, it is more distinct than many nearby ridge summits because it exceeds the commonly referenced 300-foot prominence threshold used in some mountain lists.

For more information about these measurements, see What Is Mountain Prominence? and What Is a Parent Peak?.

🪨 Geology

Bighorn Mountain belongs to the geologically complex southeastern San Bernardino Mountains, where tectonic uplift, faulting, and erosion have produced some of Southern California’s most dramatic relief.

The wider region lies near the San Andreas Fault system and the complicated fault networks surrounding San Gorgonio Pass. Interactions between the Pacific and North American tectonic plates have compressed and uplifted sections of the crust, helping create the high mountains north of the pass.

Much of the San Gorgonio high country consists of crystalline bedrock, including granitic and metamorphic rocks exposed by uplift and erosion. These resistant rocks form the mountain’s ridges, broken outcrops, and steep slopes.

Weathering has produced extensive areas of loose sand, gravel, and unstable scree. Hikers approaching Bighorn directly from The Tarn may encounter particularly steep, unconsolidated slopes, making careful route selection important.

The broader San Gorgonio massif also preserves evidence of past glaciation, an unusual feature in Southern California. During colder periods of the Pleistocene, mountain glaciers shaped portions of the surrounding high country and contributed to the formation of cirques, basins, and glacially influenced valleys.

Today, Bighorn’s exposed ridgeline offers a close look at the processes that continue to shape these mountains: freeze-thaw weathering, rockfall, erosion, and occasional powerful storms.

🌿 Flora & Fauna

The landscape surrounding Bighorn Mountain changes dramatically with elevation. Approaches beginning near Forest Falls pass through warmer canyon environments before entering montane forests and, eventually, the sparse subalpine terrain surrounding the summit.

At middle elevations, hikers may encounter Jeffrey pine, white fir, incense cedar, and other conifers typical of Southern California’s mountain forests. Shaded drainages support additional vegetation wherever seasonal water is available.

Higher on the mountain, lodgepole pine and limber pine become more characteristic. On especially exposed ridges, trees may grow in twisted, stunted forms shaped by strong winds, cold temperatures, and heavy winter snow.

Near the summit, vegetation becomes increasingly scattered. Rocky ground, thin soils, intense sunlight, and a short growing season limit plant growth, creating an open landscape of hardy shrubs, grasses, and isolated high-elevation plants.

Wildlife in the broader San Gorgonio Wilderness includes mule deer, black bears, mountain lions, coyotes, bobcats, and numerous smaller mammals. Mountain birds, raptors, and other species move between the forested valleys and exposed high country.

Although Bighorn Mountain carries the name “Bighorn,” visitors should not assume that bighorn sheep are commonly encountered on the summit. Bighorn sheep occur in parts of the broader Southern California mountain and desert landscape, but sightings depend heavily on location, habitat, season, and chance.

As with any wilderness trip, wildlife should be observed from a distance. Food should be stored securely, and hikers should avoid disturbing fragile vegetation or creating unnecessary new paths across the upper slopes.

🥾 Hiking & Climbing Routes

Bighorn Mountain is a demanding destination regardless of approach. Its elevation exceeds 11,000 feet, routes involve substantial climbing, and the final summit typically requires leaving a maintained trail.

The easiest route technically is not necessarily the safest or most accessible on a given day. Snow, wildfire damage, road closures, fallen trees, and changing permit requirements can affect every approach.

Vivian Creek Approach

The Vivian Creek Trail begins near Forest Falls at approximately 6,000 feet. It is best known as the shortest major approach to San Gorgonio Mountain, but it also provides access to Bighorn for experienced hikers.

The trail climbs steeply from the Mill Creek drainage before passing Vivian Creek Camp, Halfway Camp, and High Creek Camp. These landmarks provide useful reference points as the route gains elevation through forest and increasingly exposed mountain terrain.

From the upper Vivian Creek Trail, experienced hikers may leave the maintained route and navigate cross-country toward the saddle below Bighorn Mountain. A more direct variation described by the Sierra Club’s Hundred Peaks Section is approximately 14 miles round trip with around 5,000 feet of elevation gain, but it requires reliable navigation and confidence on steep, uneven ground.

Another option continues toward San Gorgonio Mountain before descending southeast toward The Tarn and climbing Bighorn from its northwest side. This version is longer but allows hikers to combine both major summits.

A demanding loop connecting San Gorgonio Mountain, Bighorn Mountain, and Dragons Head has been documented at approximately 18.6 miles with about 6,100 feet of total elevation gain. Its cross-country sections can reach Class 2 difficulty.

South Fork and Sky High Trail Approach

The South Fork Trail begins near Jenks Lake Road and enters the northern side of the San Gorgonio Wilderness. From South Fork Meadows, hikers can continue toward Dry Lake and Mineshaft Saddle before joining the Sky High Trail.

As the Sky High Trail traverses the upper slopes of San Gorgonio, Bighorn Mountain becomes visible to the south. Hikers can descend off-trail toward The Tarn, cross the basin, and climb the mountain’s northwestern ridge.

The South Fork approach is generally long, but it offers access to established backcountry camps and can work well as an overnight backpacking trip when permits and campsite availability allow.

Dry Lake should not be assumed to contain water simply because of its name. Water conditions throughout the wilderness change seasonally, and any natural water collected in the backcountry should be treated before drinking.

Fish Creek Approach

Historically, the Fish Creek Trail has provided one of the most direct northern approaches to Bighorn Mountain.

The traditional route begins near 8,040 feet and follows the Fish Creek Trail toward Fish Creek Saddle and Mineshaft Saddle. From there, hikers join the Sky High Trail before leaving the maintained trail to cross The Tarn and ascend Bighorn’s ridge.

The Hundred Peaks Section describes this route as approximately 18 miles round trip, with about 4,200 feet of cumulative elevation gain. While much of the route follows established trails, the final approach to Bighorn includes cross-country travel.

Access warning: The San Gorgonio Wilderness Association currently reports that roads 1N02 and 1N05 are closed, limiting direct access to the Aspen Grove and Fish Creek areas. When these closures are in effect, hikers should not assume that the traditional Fish Creek Trailhead can be reached by vehicle. Check current road and trail conditions before planning this approach.

Approaching Through The Tarn

The Tarn is the broad, relatively flat basin separating Bighorn Mountain from the upper slopes of San Gorgonio.

Although its name suggests a small mountain lake, the basin is often dry. It should be treated as a navigation landmark rather than a dependable water source.

From the basin, the mountain’s northwest side generally offers a more manageable approach than climbing directly up the steep, loose northern slope. The final ascent involves uneven ground, sandy sections, and occasional brush.

Once on the ridge, hikers continue toward the high point while watching their footing and avoiding unnecessary disturbance to sensitive vegetation.

Permits, Parking, and Safety

A free wilderness permit is required for both day hikes and overnight trips in the San Gorgonio Wilderness. Permits are limited and currently issued online through the San Gorgonio Wilderness Association.

Some developed trailhead parking areas also require an Adventure Pass or another accepted recreation pass. Parking requirements depend on the location, so visitors should check the current rules for their chosen trailhead.

Other important considerations include altitude, heat at lower elevations, cold winds near the summit, unreliable water, wildfire conditions, and limited cellular service.

Before leaving, carry the equipment described in The Ten Essentials for Hiking and make sure someone knows your intended route and expected return time.

🏔️ Field Guide Tip: Approach Bighorn Mountain from the northwest side of The Tarn when conditions permit. The direct northern slope can be loose and unpleasant, while the more gradual ridge approach generally provides better footing and simpler navigation.

🌤️ Best Time to Visit

For most hikers, the best season to climb Bighorn Mountain is summer through early fall, when the high-country trails are more likely to be free of significant snow.

Summer

Summer generally provides the most predictable access to the San Gorgonio high country. Long daylight hours are especially valuable because most Bighorn Mountain routes require a full day of hiking or an overnight trip.

Conditions can vary substantially between the trailhead and summit. Lower canyons may be hot, while the upper mountain remains cool, windy, and exposed.

Afternoon thunderstorms occasionally develop over Southern California’s highest mountains. Begin early, monitor the forecast, and avoid exposed ridges if lightning threatens.

Fall

Early fall often brings cooler hiking temperatures, reduced summer crowds, and clear mountain views. It can be an excellent season for experienced hikers, provided that roads and trails remain open.

However, storms can arrive early at elevations above 11,000 feet. Shorter daylight hours also make navigation delays more consequential.

Winter

Winter transforms Bighorn Mountain into a serious mountaineering objective. Deep snow, hard ice, severe wind, freezing temperatures, and difficult route-finding can make even familiar trails hazardous.

The cross-country approach near The Tarn may be especially challenging when terrain features are buried or steep slopes are icy. Depending on conditions, winter travel may require mountaineering equipment, advanced snow-travel skills, and sound avalanche awareness.

Spring

Spring conditions depend on the previous winter’s snowfall and current temperatures. Lower trails may appear dry while shaded slopes and upper basins still hold significant snow.

Stream crossings may also become more difficult during snowmelt. Hikers should rely on current trail reports and weather forecasts rather than assuming that warm conditions in nearby valleys mean the summit is accessible.

🧭 Nearby Mountains & Attractions

San Gorgonio Mountain

San Gorgonio Mountain rises immediately northwest of Bighorn Mountain and is the highest summit in Southern California. Depending on the dataset, its elevation is approximately 11,499 to 11,503 feet.

Experienced hikers sometimes combine San Gorgonio and Bighorn on the same demanding outing.

Dragons Head

Dragons Head is a nearby summit southwest of Bighorn Mountain, rising to approximately 10,862 feet. Its position above Mill Creek Canyon provides dramatic views and makes it a possible addition to a challenging cross-country loop.

Routes connecting Bighorn and Dragons Head require careful navigation and should be attempted only by hikers comfortable traveling beyond maintained trails.

Jepson Peak

Jepson Peak stands west of San Gorgonio Mountain and ranks among the highest summits in Southern California. It is named for botanist Willis Linn Jepson and is often visited during longer traverses of the high San Bernardino crest.

Anderson Peak

Anderson Peak lies farther west along the San Bernardino Divide. Its summit reaches approximately 10,871 feet, making it another significant high-country destination within the wilderness.

San Bernardino Peak

San Bernardino Peak occupies the western portion of the high San Bernardino crest and is one of the region’s classic strenuous hiking destinations.

Long-distance hikers sometimes connect multiple peaks along the divide, although such traverses require careful attention to mileage, water availability, and permit requirements.

San Jacinto Peak

San Jacinto Peak rises south of San Gorgonio Pass in the separate San Jacinto Mountains. Its distinctive high summit can be visible from Bighorn Mountain during clear weather.

The two mountain groups create one of Southern California’s most dramatic contrasts between high-elevation wilderness and the nearby desert floor.

Dry Lake and Dollar Lake

Dry Lake and Dollar Lake are popular destinations on the northern side of the San Gorgonio Wilderness.

These high-country basins provide scenic backpacking opportunities and access to longer routes toward San Gorgonio, Bighorn Mountain, and the surrounding ridges. Water availability varies considerably with season and precipitation.

💡 Fun Facts

Modern elevation data places Bighorn Mountain slightly above 11,000 feet, although older references commonly list it at 10,997 feet.
A historical wilderness map published in 1971 recorded the summit at approximately 11,005 feet.
The Sierra Club’s Hundred Peaks Section added Bighorn Mountain to its peak list in December 2000.
The mountain is not consistently identified by name on older USGS or Forest Service maps.
Bighorn Mountain lies southeast of Southern California’s highest summit, San Gorgonio Mountain.
The broad basin separating Bighorn and San Gorgonio is known as The Tarn, even though it is often dry.
Bighorn Mountain is different from Bighorn Peak near Ontario Peak in the San Gabriel Mountains.
It is also separate from the lower-elevation Bighorn Mountain Wilderness east of the main San Bernardino high country.
Despite its name, the summit should not be promoted as a guaranteed or regular location for seeing bighorn sheep.
The peak offers experienced hikers an opportunity to leave the crowded San Gorgonio summit routes and explore a quieter portion of the wilderness.

❓ FAQ

How high is Bighorn Mountain?

Modern Peakbagger data places Bighorn Mountain at approximately 11,006 feet, or 3,355 meters. Older hiking references commonly list the summit at 10,997 feet.

Where is Bighorn Mountain located?

Bighorn Mountain is in the San Gorgonio Wilderness of the San Bernardino Mountains in San Bernardino County, California.

Is Bighorn Mountain the same as Bighorn Peak?

No. Bighorn Mountain is an approximately 11,006-foot summit near San Gorgonio Mountain. Bighorn Peak is a separate mountain in the San Gabriel Mountains near Ontario Peak.

Is Bighorn Mountain inside Bighorn Mountain Wilderness?

No. This Bighorn Mountain lies within the San Gorgonio Wilderness. The separate Bighorn Mountain Wilderness occupies lower terrain farther east.

What is Bighorn Mountain’s nearest higher neighbor?

San Gorgonio Mountain is Bighorn Mountain’s nearest higher neighbor and parent peak.

How much prominence does Bighorn Mountain have?

Bighorn Mountain has approximately 399 feet, or 122 meters, of topographic prominence.

Is there a maintained trail to the summit?

No maintained trail runs directly to Bighorn Mountain’s summit. Hikers generally follow established wilderness trails before completing the final approach cross-country.

What is the best route up Bighorn Mountain?

The most appropriate route depends on current road access, snow conditions, experience, and fitness. Vivian Creek provides a direct southern approach, while South Fork can provide access from the north. The traditional Fish Creek route is dependent on road conditions and closures.

How difficult is the hike?

Bighorn Mountain is a strenuous objective because of its long approach, major elevation gain, high altitude, and off-trail navigation. Depending on the route, hikers may encounter Class 1 terrain with cross-country travel or Class 2 scrambling.

Do you need a permit to hike Bighorn Mountain?

Yes. Free wilderness permits are required for both day hikes and overnight trips within the San Gorgonio Wilderness.

Can you hike Bighorn Mountain from Fish Creek?

Historically, yes. However, access can be affected by closures of Forest Roads 1N02 and 1N05. Check current official road and trail conditions before relying on the Fish Creek approach.

Is The Tarn a reliable water source?

No. The Tarn is frequently dry and should not be considered a dependable source of drinking water.

Can beginners hike Bighorn Mountain?

Bighorn Mountain is generally not an appropriate first mountain hike. The elevation, distance, navigation requirements, and potential exposure make it better suited to experienced hikers.

Are bighorn sheep commonly seen on the mountain?

Sightings should not be expected. Although bighorn sheep occur in portions of the broader regional landscape, the mountain’s name does not guarantee that visitors will encounter them.

Can Bighorn Mountain and San Gorgonio Mountain be climbed together?

Yes. Experienced hikers sometimes combine the summits, occasionally adding Dragons Head as well. These outings involve considerable elevation gain, long mileage, and cross-country navigation.

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