The Greenback Cutthroat Trout (Oncorhynchus clarkii stomias) is a subspecies of Cutthroat Trout native to the rivers and streams of Colorado. Distinguished by its bright red or orange throat markings and vibrant coloration, it was historically found throughout much of the South Platte River basin. However, habitat loss, overfishing, and hybridization with non-native rainbow trout led to a dramatic decline in greenback cutthroat populations, and by the 1930s, it was believed to be extirpated in the wild. Through concerted conservation efforts, including the protection and restoration of its native habitats, the establishment of hatchery programs, and the removal of invasive species, greenback cutthroat trout have been successfully reintroduced to several streams in their historical range. Conservation measures continue to focus on maintaining genetic integrity, restoring cold-water habitats, and monitoring populations to ensure the long-term survival of this iconic fish.