Castle Peak rises above Castle Pass near Donner Pass in California’s Sierra Nevada, within Tahoe National Forest near major roads and trails. Originally named Mount Stanford by the Whitney Survey from 1860 to 1874 after Leland Stanford, it later took its current name from its conical, fortress-like summit, which makes it a prominent local landmark. Its alpine setting is shaped by Pacific storms forced upward over the range, bringing exceptional snowfall to the Donner Pass area and creating a snowy subalpine landscape. Easily reached from the trans-Sierra route, the mountain is popular for hiking and backcountry skiing, though its heavy snow can also be deadly, as shown by the avalanche of February 17, 2026.