Colorado River cutthroats are thought to have occupied the basin of upper Muddy Creek , a tributary of the Little Snake River ( which ultimately flows into the Colorado River ) in southern Carbon County , Wyoming . Historical accounts in letters and diaries refer to them as " mountain trout " or " speckled trout . " The fish may have begun to disappear from the upper Muddy Creek in the 1850s as a result of physical changes made to the environment by travelers , the introduction of the brook trout and other non-native species , and possibly the over-trapping of beavers , which affected dams and dependent habitats . A distinct lineage of Colorado River cutthroat trout known as the San Juan cutthroat was also found in the San Juan River and its tributaries , and was identified in 2012 by genetic testing of two specimens collected in 1874 near Pagosa Springs . While feared extinct , 8 isolated populations were discovered in and around the San Juan National Forest in mid-2018 . Shortly after the rediscovery of the San Juan cutthroat , their remnant populations were threatened by the 416 Fire , which was closing in on their remaining habitat . In response , 58 San Juan cutthroats were removed from two remote creeks north of Durango and are being held in hatcheries , with the ultimate goal of captive breeding and reintroduction
416 Fire
416 Fire
Colorado River cutthroat trout