DistributionRead full entry
Global Range: (20,000-200,000 square km (about 8000-80,000 square miles)) Historically this subspecies occurred in the Yellowstone River drainage in Montana and Wyoming and in the Snake River drainage in Wyoming, Idaho, Utah, Nevada, and probably Washington (Gresswell 2009). About 99 perent of the historically occupied stream habitats were in Wyoming, Idaho, and Montana (May et al. 2007).
Native to the Snake River system above Shoshone Falls (except for waters between Jackson Lake and Palisades Reservoir) and Yellowstone River drainage downstream to the Tongue River; also native to the Goose Creek drainage in Nevada and the Raft River drainage in northwestern Utah (extirpated in the latter area) (Behnke 2002). Lakes with large populations include Yellowstone Lake and Henry's Lake; the latter population is slightly hybridized (Behnke 1992). In the upper Snake River drainage and in tributaries of the Yellowstone River downstream from Yellowstone Park, this subspecies has been largely replaced by non-native and/or hybrid trout (Behnke 1992, 2002). Over the past several decades, millions have been stocked outside the native range, especially in the native range of the westslope cutthroat trout (Behnke 1992).