The San Gorgonio Wilderness is home to several distinct biotic communities. These include: chaparral, yellow-pine forest, montane meadows, lodgepole forest, sub-alpine and alpine fell.
During the Pleistocene period, the Wilderness was home to at least seven cirque and valley glaciers heading at elevations between 10,300 and 11,300 and ranging from ½ mile to 1 ¾ miles in length. None descended below 8,700 feet. Today, one can identify the ancient glaciation by obvious cirques and large medial and terminal moraines up to 700 feet in height, one of which formed Dollar Lake.![]() |
Common Rock Types:
Muscovite Biotite Gneiss![]() Location: Grinnell Mountain Age: Proterozoic (1.76 billion years) Description: A metamorphic rock with well-developed, planar layering and linear fabric, typical of rocks on the slopes north of Dry Lake, San Gorgonio Wilderness. |
Muscovite Biotite Migmatitic Gneiss![]() Location: San Gorgonio Mountain Age: Uncertain, probably Cretaceous (80 million years) Description: A metamorphic rock with well-developed, convolute layering, cut by light tan granite dikes, typical of rocks on the north slope of San Gorgonio Mountain, San Gorgonio Wilderness. |
Muscovite Biotite Granite![]() Location: San Gorgonio Mountain Age: Uncertain, probably Cretaceous (80 million years) Description: An igneous rock without visible layering, typical of rocks along the summit ridge of San Gorgonio Mountain, San Gorgonio Wilderness. |
Mammals:
Chipmunk Tamias spp.(species unidentified) Golden-mantled Ground Squirrel, Spermophilus lateralis Western Gray Squirrel , Sciurus griseus Black Bear, Ursus americanus Bighorn Sheep, Ovis canadensis nelsoni Mountain Lion, Felis concolor Coyote, Canis latrans Mule Deer Odocoileus hemionus |
Trees:
Black Oak, Quercus kelloggi Mountain Mahogany, Cercocarpus ledifolius Coulter Pine, Pinus coulteri White Fir, Abies concolor Limber Pine, Pinus flexilis Lodgepole Pine, Pinus contorta Jeffrey Pine, Pinus jeffreyi Ponderosa Pine, Pinus ponderosa Incense Cedar, Calocedrus decurrens Sugar Pine, Pinus lambertiana Black Cottonwood, Populus trichocarpa Quaking Aspen, Populus tremuloides |
Shrubs and other plants:
Bracken Fern (Pteridium aquilinum) Manzanita (Arctostaphylos spp.) Chinquapin Scrub Oak Willow Stinging Nettle Whitethorn Wild Buckwheat Elderberry Wax Current Sierra Gooseberry Rabbitbrush Yucca Sedges Bush Monkeyflower Miner’s Lettuce Coffeeberry Wild Rose |