Westslope Cutthroat Trout - Montana Fly Fishing Species
Westslope cutthroat trout join Yellowstone cutthroat trout as Montana’s state fish.
Like Yellowstone cutthroat trout, Westslope cutthroat have a distinctive fiery slash under their jaw.
Westslope are defined by smaller spots than other cutthroat subspecies, concentrated mostly below the lateral line and towards the tail. Their silver bodies glimmer with golden hues, though some express more vibrant yellow, orange, and red than coastal or Yellowstone relatives.
When hybridized with Yellowstone cutthroat, spotting and coloration blend between the two types. Rainbow trout hybrids sport telltale spots on the head and forward lower flank.
Westslope cutthroat trout (Oncorhynchus clarkii lewisi) hold a storied place amongst Montana's fish. They were once found from the Continental Divide westward and throughout the Missouri River's headwaters. But habitat destruction and rampant hybridization with nonnative rainbow and Yellowstone cutthroat trout have fractured their native range.
Listed as a Montana Fish of Special Concern, remaining pure populations of westslope cutthroat endure via conservation stocking programs. These are now, once again, widely distributed throughout the upper Missouri River Basin because of ambitious restocking programs.
Continued conservation can preserve the westslope cutthroat trout's unique place in Montana's waters.
Bozeman fly fishing trips with our team of expert guides find westslope cutthroat trout on the Gallatin, lower Madison, and Jefferson rivers.
Typically measuring 6-16 inches in their stream and lake habitats, westslope cutthroat rarely exceed 18 inches.