Ansel Adams Wilderness - Geography and Geology

Geography and Geology

The Ansel Adams wilderness spans in elevation from 3,500 to 13,157 feet (1,100 to 4,010 m), forming the northern end of the High Sierra.

The centerpiece of the Ansel Adams wilderness is the Ritter Range, which includes dark metavolcanic glaciated mountains such as Mount Ritter, Banner Peak, and The Minarets.

Immediately to the east of the Ritter Range is the Middle Fork of the San Joaquin River, which contains Devils Postpile, a series of basaltic columns that were revealed and smoothed by glacier action. The Middle Fork originates from Thousand Island Lake, at the foot of Banner Peak, one of the largest backcountry lakes in the Sierra.

To the east of the Middle Fork canyon is the true Sierra Crest, which, at roughly 10,000 feet (3,000 m) of elevation is lower than the Ritter Range. This relatively low region of the Crest allows winter storms through and cause large amounts of snowfall on Mammoth Mountain, which sits in the gap. The gap also allows migration of plants and animals across the Sierra Crest.

To the west of the Ritter Range lies the canyon of the North Fork of the San Joaquin, a relatively remote and unvisited high-country area. The southern part of the wilderness contains the 3,000 feet (900 m) deep canyon of the main San Joaquin River, which flows out of the Sierra Nevada to California's Central Valley.