Little Walker Caldera is a depression in the eastern Sierra Nevada that is adjacent to the Sweetwater Mountains. The caldera is very large, measuring about in diameter. The Little Walker Caldera is named for the Little Walker River; it is the river that is little, not the caldera. U.S. Route 395 in California crosses the Northern boundary of the caldera, just west of the Devil's Gate Pass. California State Route 108 follows more of the northern boundary of the caldera.