Colorado River Cutthroat
Historically, Colorado River Cutthroat Trout were found throughout portions of the Colorado River drainage in Colorado, southern Wyoming, eastern Utah, northeastern Arizona, and northwestern New Mexico. Due to completion with other species and habitat degradation it is estimated that this cutthroat occupies less than 5% of its historical range, primarily in high mountain streams. Currently, approximately 100 pure-strain populations exist, mostly in small, isolated streams. Like most trout species, Colorado River cutthroat require clear, cold water of streams, rivers, and small to medium sized lakes.
Cutthroat trout are named for the reddish/orangish slash under its jaw. Giving the appearance that fish’s throat was cut. Colorado River cutthroats are among the most colored of the cutthroats. While their color varies from location, they generally have greenish hued backs transitioning to golden-yellowish side, sometimes with orange hues. Some fish may sport bright reddish colored bellies, especially males during spawn. They all have large spot uniformly distributed over the body and tail. Unlike rainbow trout it lacks white tips on the fins. As most Colorado River cutthroat trout are found in small, headwater streams, typically they are under 10 inches, but in lakes and rivers they can reach 20 inches or so.
Sexually mature at two to three years of age, cutthroats spawn in the spring. A red is built in a gravelly area, where the female lays her eggs. The male simultaneously deposits his milt over the eggs. The fertilized eggs are then covered with gravel. Fry emerge in late July through early September, about six weeks after spawn.
In lakes cutthroat feed on plankton and aquatic insects. In streams a variety of aquatic and terrestrial insects make up the bulk of their diet. Larger fish, over 12 inches will feed on small fish and crayfish.
Colorado River Cutthroat in Wyoming
- Body is bright, golden yellow with a brassy green back, the most colorful Wyoming cutthroat
- Large spots distributed uniformly on body and caudal fin, which can be rectangular in shape
- Adipose fin usually has a black border
- Orange tint along belly
- Red or orange slash mark under jaw
- Distinguished from other cutthroat subspecies by its bright colors and large spots
- Distinguished from rainbow trout by the lack of white tips on fins
The Colorado River cutthroat trout is native to the Green River and Little Snake River drainages in Wyoming. In fact, they were the only trout found in those drainages. Numbers of Colorado River cutthroats were reduced through hybridization and competition with introduced non-native trout, like the brook trout and rainbow trout.
Colorado River cutthroat prefer small, clear streams and rivers along with small to medium size lakes. Cutthroat are spring spawners. The principle food of the cutthroat is plankton and aquatic insects in lakes, and aquatic insects in streams. Cutthroat over 12 inches often feed on small fish and crayfish.