Greenback Cutthroat Trout
Oncorhynchus clarkii stomias
The greenback cutthroat trout (Oncorhynchus clarkii stomias) is the easternmost subspecies of cutthroat trout. The greenback cutthroat, once widespread in the Arkansas and South Platte River drainages of Eastern Colorado and Southeast Wyoming, today occupies less than 1% of its historical range. It is currently listed as threatened under the Endangered Species Act. It was adopted as the state fish of Colorado on March 15, 1994 replacing the unofficial rainbow trout. In 2012, a genetic study that compared DNA samples both from modern populations and historical samples dating back to the 19th century revealed that the only remaining population of pure greenback cutthroat trout is found in a 4-mile (6.4 km) stretch of Bear Creek, a tributary of the Arkansas River. Many of the populations previously identified as greenback cutthroat were actually of the similar Colorado River and Rio Grande cutthroat subspecies.
Colorado River Cutthroat Trout by Western Native Trout Initiative
Greenback Cutthroat Trout by By Dub Paetz/Troutster.com