Colorado's Cutthroat Diversity

This past summer I had the privilege to make two trips out to the Colorado Rockies in pursuit native Cutthroat. While my original goal was just to catch the two subspecies of Cutthroat that I had yet to catch, I ended up expanding my second trip to pursue all of the extant Cutthroat lineages in the state and here they are.

Green River Cutthroat - Blue lineage - Yampa drainage

The Green River Cutthroat or Blue lineage of the Colorado River Cutthroat are found in streams draining to the Green River, such as the White River and Yampa River drainages. These Cutthroat were also stocked extensively across much of the state and are found in many streams in the upper Colorado, Gunnison, Dolores and San Juan watersheds.

Colorado River Cutthroat - Green lineage - Upper Colorado River

The Colorado River Cutthroat or Green lineage of the Colorado River Cutthroat. These fish are native to the Upper Colorado, Gunnison and Dolores watersheds. These fish were only recognized as being distinct from the Green River Cutthroat in recent years and currently only occupy about 3% of their native range.

Hayden Creek Cutthroat - Arkansas drainage Colorado River Cutthroat

While the extinct Yellowfin Cutthroat is recognized as the native trout of the Arkansas watershed, historic accounts indicate that ‘Greenback Cutthroat’ were also found in Twin Lakes in the upper Arkansas watershed. While both the Yellowfin and ‘Greenbacks’ vanished from Twin Lakes in the early 1900’s, a single population of fish found in the South Prong of Hayden Creek matched the ‘Greenback’ museum specimens from Twin Lakes. However in a twist of the story, the genetic analysis also revealed that these fish were not Greenbacks but a unique population of Colorado River Cutthroat with genes found nowhere else. While the South Prong Hayden Creek population was lost in a Fire, Colorado Parks and Wildlife has established a handful of populations across the Arkansas basin.

San Juan Cutthroat - San Juan drainage

The San Juan Cutthroat are native to the upper San Juan River basin. Until recently these fish were believed to be Colorado River Cutthroat, but genetic analysis of museum specimens showed that they represent a unique lineage of Cutthroat. At the time of this revelation, it was believed that the San Juan Cutthroat were extinct, but an extensive search of the basin turned up a handful of small isolated populations scattered across the upper watershed.

Greenback Cutthroat - South Platte drainage

The Greenback Cutthroat are native to the South Platte drainage and have a complex story. These fish were believed to be extinct by the 1930’s, but when a few small Cutthroat populations were discovered in the basin a recovery program was launched. For years this program was considered a huge success story, until genetics work showed that the fish used for the program were a mix of Green River and Colorado River Cutthroat and only a single population of a few hundred Greenbacks remained. After resetting the conservation efforts, Greenbacks have been reestablished in a handful of streams across the front range of Colorado.

Rio Grande Cutthroat - Upper Rio Grande drainage

The beautiful Rio Grande Cutthroat are found in the upper Rio Grande watershed of Colorado. These fish are the southernmost Cutthroat lineage and similar to the other Cutthroat of Colorado are now restricted to small headwater streams across their native range.