Asbestos Mountain: Big Plants, Big Rocks, Big Views and No Crowds

Asbestos Mountain is one of those not often discussed summits that sits on the edge of the Coachella Valley. Not famous like San Jacinto or Tahquitz, but stubbornly present as a rocky crown on the eastern side of the Santa Rosa Mountains. Asbestos Mountain is perfect for hikers who like a short, nontechnical scramble with excellent vistas. It's not for hikers who need a well-marked trail or who are uncomfortable route finding over a rocky terrain.

Hike Distance: 3.17 miles

Elevation Gain: 987 feet

TrailsNH Hiking Difficulty Calculator: 79 – Moderate

Click here to navigate to the TrailsNH website for a description of the hiking difficulty calculator 

Asbestos Mountain Elevation Peak: 5,265 feet

Prominence: 1,265 feet

Trailhead Location: 33.61977, -116.46232 

What's with the Name of the Mountain

This photo taken from a pull off on Highway 74 shows the knobby ridge that Asbestos Mountains sits on. The arrow indicates it's approximate location. The name Asbestos Mountain isn’t poetic — miners really did come here, as early as 1888 (John D Hoff Co.) looking for asbestos, the fibrous mineral once prized for its fireproofing. But why here, and not in every patch of granite in the desert?

The story begins deep underground. After the granite of the Santa Rosas cooled, circulating hot water moved through its natural cracks and joints. These fluids carried magnesium, silica, and other elements. Under the right conditions of heat and pressure, they reacted with bits of magnesium-rich rock in the crust, forming fibrous chrysotile asbestos along fracture zones. The result: thin, pale-green veins of asbestos filling cracks in the mountain. These veins were never huge, more ribbons than mother lodes, but they were enough to draw prospectors in the early 20th century, when asbestos was in demand for insulation, brake linings, and heatproof materials. In the Santa Rosas, the deposits were small and localized, tied to very specific geologic conditions. Miners dug short tunnels and pits, leaving scars still visible on the slopes, before the effort fizzled out. Unfortunately, the link between asbestos and lung cancer wasn't reported until the early 1940s.

Unless you venture to specific mining locations, not on the trail, and aggressively dig and disturb remaining mining waste piles, there is no health hazards associated with this hike. As always treat old mine areas with caution and respect

My path to and from the summit is highlighted on this satellite view.

Let's Start Hiking Asbestos Mountain

I reached Asbestos Mountains via Jeraboa Road, which is situated in the Pinyon Pines area off Highway 74. The dirt roads in Pinyon Pines are generally well-maintained, and Jeraboa Road was no different. I drove to its end, stopped at the National Forest Boundary marker, parked the car, and started hiking along the old road.

The summit is not visible from the unofficial trailhead, but the rock outcropping located on the ridge left of center will serve as a useful visible marker during this hike. I decided to delay selecting a route until I reached the base and had a closer look at my options.

Big Plants

Right from the start, it's clear we are hiking in the transition zone where desert scrub blend into the Pinyon-juniper plant community. Wandering off the road meant having to dodge all types of spiny plants. The landscape was a dense garden of Gander's cholla.

Although we frequently see Gander cholla during our hikes, these cacti are found only in a limited area of Southern California (yellow highlighted area) and Mexico. Once you exit the Sonoran Desert, you leave the Gander cholla behind.

This cactus is well adapted to the harsh desert climate. Its segmented stems are covered

in both dense spines and glochids, which are barbed, bristle-like hairs found in the small bumps on the cactus's surface. The presence of both, along with their dense nature, helps to differentiate it from other similar species.

Ganders often grow in shrubby clumps. Unlike the Teddy-bear cholla, the 1-2 inch wide and 4-10 inch long green segments are firmly attached and don't fall to the ground.

The presence of junipers signaled the transition zone where both desert scrub and the Pinyon-juniper plant community thrive. In the mid-elevations of the San Jacinto and Santa Rosa mountains, junipers form a rugged, open woodland that testifies to their ability to endure extremes. Typically found between 4,000 and 6,500 feet, these trees anchor rocky slopes and alluvial fans where soils are thin, moisture is scarce, and summer heat can be intense. Junipers depend on winter precipitation to recharge soil moisture, and warming temperatures threaten to shift the snow–rain balance, leaving less water available during the growing season. Unlike higher-elevation conifers, junipers cannot easily retreat upslope, as suitable soils and space become limited. This makes mid-elevation juniper woodlands a potential bellwether for climate change in southern California’s mountains, highlighting both their resilience and their precarious future.

Junipers survive here through a suite of drought-adaptive traits: their roots probe deeply for groundwater while also spreading widely to capture brief rains; their small, scale-like leaves reduce surface area and water loss.

Mojave yucca also lined the road leading to the mountain. It's hard to miss these yucca with their spikey, dagger-like leaves. Although Mojave yucca are most common in the Mojave Desert, they are also widespread in the Sonoran Desert. They serve as a transitional species between the lower desert scrub and the higher elevation more densely wooded areas in the Santa Rosa Mountains.

Typically leaves measure 12 to 59 inches and have long fibrous threads peeling from the edges of the leaves. These fibers distinguish Mojave yucca from Joshua tree which from a distance can look familiar. These yucca grow slowly and have a long lifespan, reportedly living up to 200 years.

The Mojave yucca is an evergreen shrub or small tree that can grow to a height of 5 to 16 feet. Under ideal conditions, some mature specimens have been known to reach heights of up to 30 feet. On the mountain slopes, several of the yucca had more of a tree-like appearance.

Desert agaves were another type of spiked plant found in abundance on the flat area before the base of the mountain.

In less than a mile I reached the base of the mountain. It was decision time—choosing a route. One option was to hike up the gully between the 2 hills or attack the slope to the left of the gully. I chose the gully approach.

Once I started the climb, I noticed several small cairns which I hoped indicated a descent route through the rock piles, cacti and shrubs.

Looking back at the Santa Rosa Mountains where the snow-line clings to elevations between 5,000 and 7,000 feet.

The initial climb involved dodging trees, cacti, and various desert shrubs.

I took care to avoid the pancake prickly pear cactus nestled among the rocks. The pancake prickly pear is a shrub or small tree-like cactus with flat, rounded, bluish-green pads that grow up to 15-18 inches in diameter, giving it a 'pancake' appearance. It is typically 1-8 feet tall, with a trunk. It is usually found growing on very steep hillsides in mountainous terrain where it endures extreme temperature fluctuations and prolonged drought.

Its flattened pads contain water and nutrients, making them valuable forage for jackrabbits, packrats and desert tortoises. Similar to gander cholla, the pads are covered in long spines and glochids.

Looking down at the segment I had climbed. The initial elevation gains came quickly but now I had to slow down and scramble more.

The next section required more lateral movements to navigate around the boulders.

Several large Pinyon pines were growing on the slopes. At mid-elevations in the San Jacinto and Santa Rosa mountains, pinyon pines anchor the dry slopes with their gnarled, gray-green crowns. These hardy conifers thrive between roughly 4,000 and 7,000 feet, where summer heat is tempered by occasional monsoon moisture and winter storms still bring some snow. Their survival strategy is rooted in drought tolerance: deep roots tap scarce groundwater and small, waxy needles to help minimize water loss.

Pinyon pines are relatively slow growers. They reach maturity after about 20 years, but don’t produce female cones until they are some 40 years old. Even then, their pine cone production is sporadic, with abundant crops occurring every 2 to 7 years followed by multiple years of low cone production, a phenomenon known as masting. Trees typically begin producing their first cones around 35-40 years old and substantial seed crops much later. That slow life cycle means the trees can’t bounce back from die-offs due to drought or wildfire as quickly as some other species.

Pinyon pines occupy a narrow climatic band, vulnerable to both hotter temperatures and declining precipitation. Recent studies have shown a significant decline in pine cone production, with reproduction being inhibited by rising temperatures. This creates a bottleneck for future regeneration, especially since pinyon pines reproduce in large quantities only every few years. If warming trends continue, the mid-elevation zone, in areas like Asbestos Mountain, may become too arid for regeneration, squeezing pinyons upslope into thinner habitat.

Big Rocks

After 900+ feet of elevation, I reached the rock outcropping on the ridgeline that I mentioned before.

As I climbed out of the gully, the terrain leveled out. I was looking at several possible rocky summits but based on my research, I knew to head to the rock pile on the left.

The landscape surrounding the summit was dotted with 'stacked rock' formations similar to those found in Joshua Tree National Park. This isn’t surprising since both landscapes were built from the same ancient granite and sculpted by the same natural forces.

Approximately 100 million years ago, magma slowly cooled beneath the Earth's surface, forming coarse-grained granites. As the granite cooled and was eventually uplifted towards the surface, it developed fractures along natural joints, breaking into large blocks.

But granite isn't as tough as you think. Granite breaks down chemically when exposed to water. Over time, water infiltrated these joints, initiating the chemical weathering process, which gradually rounded the edges of the blocks. This process results in the formation of classic 'corestone' boulders—large, rounded rocks that appear as if they have been deliberately stacked.

In wetter climates, those granite blocks would have long ago crumbled into sand. But here in the desert, limited rainfall and dry air has preserved them. Flash floods sweep away the smaller light-weight rocks leaving behind the bigger heavy-weights.

At the foot of the summit, there was no straightforward path to the top, and since I was hiking solo today, I wasn't eager for a challenging climb.

I walked around the back side and found a manageable Class 2 scramble leading to the summit and ...

... a few well placed cairns to help.

Chemical weathering of the granite provided excellent hand and foot holds.

Big Views & No Crowds

Before long, I was at the summit standing by the benchmark with not a person in sight.

With a prominence of over 1000 feet, the views in every direction were incredible. To the south, the snow capped Santa Rosa Mountains.

To the southwest, Martinez Mountain and clusters of rocks on the plains directly below the summit.

To the northwest, the San Jacinto Mountains (center left) and San Gorgonio Mountain (far right) are visible. These snow-covered peaks bear the brunt of winter storms coming off the Pacific Ocean. after enjoying these views and a snack, it was time to head down.

I was able to follow cairns for most of the descent.

During the descent, I spotted several new plants that I hadn't seen on the hike to the summit. Palmer's milkvetch, also known as Palmer locoweed is commonly found in Pinyon-juniper woodlands habitat. A member of the pea family, it forms low mats of silvery, hairy leaves which in the spring is topped with clusters of purple to violet flowers. Its beauty belies a darker side: like other “locoweeds,” it produces the toxic alkaloid swainsonine, which can poison livestock, causing erratic behavior, weakness, and sometimes death, hence the name ‘loco’

Indian paintbrush is one of the most striking wildflowers in the Santa Rosa Mountains, known for its flame-red bracts. Bracts are a specialized form of leaf that protects developing flower buds from the elements. These brilliant 'painted' structures stand out against pale granite and desert scrub. Indian paintbrush's fiery display makes them easy to spot in spring.

Paintbrushes are hemiparasitic plants — they photosynthesize, but also tap into the roots of nearby shrubs and grasses for water and nutrients. This adaptation allows them to thrive in the harsh soils of the desert mountains, often appearing beside sagebrush, buckwheat, or pinyon pine. Blooming typically peaks from March to May, coinciding with pollinator activity.

White sage is a perennial shrub native to the deserts of Southern California and northern Baja California. Belonging to the mint family, it thrives in areas where summers are hot and dry, and winters bring modest rainfall. Adapted to these conditions, white sage grows on well-drained slopes, foothills, and rocky soils. The plant is distinguished by its silvery-green, lance-shaped leaves covered in fine hairs that reduce water loss and reflect sunlight. The leaves somewhat resemble brittlebush leaves except sage leaves are generally larger than brittlebush leaves.

In no time, I was off the mountain, returning to the old road, and making my way back to the car. If you're looking for a short cross-country hike that includes boulder hopping and fantastic views from the summit, then Asbestos Mountain is the perfect choice for you.

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