Castle Lake is a glacial tarn in the Ruby Mountains of Elko County, Nevada, United States. It is within the Ruby Mountains Wilderness, which is administered by the Ruby Mountains Ranger District of the Humboldt-Toiyabe National Forest. The lake is located on a shelf near the head of Kleckner Canyon, at approximately (40°34.1′N115°23.9′W), and at an elevation of 9793 feet (2985 m). It has an area of approximately 14 acres (57,000 m²), and a depth of up to 15 feet (4.6 m).