SALIDA, Colo. — After confirming the existence of two trout species that were believed to be extinct, Colorado Parks and Wildlife (CPW) aquatic biologists are on a quest to find the Yellowfin cutthroat trout which was last seen in 1904.

CPW had confirmed the existence of the native Greenback cutthroat trout and the San Juan River cutthroat trout long after they were believed to be extinct.

In 2012, Colorado’s fishing community was shocked when CPW aquatic biologists announced genetic DNA testing had confirmed a small population of spotted trout was indeed the long-lost Greenback, Colorado’s state fish. The Greenbacks were found in tiny Bear Creek in Colorado Springs – far from their native waters in the South Platte River drainage to the north.

These recent discoveries gave hope to Alex Townsend, CPW aquatic biologist, and Paul Foutz, CPW’s Southeast Region senior aquatic biologist, in finding the Yellowfin cutthroat trout that was last seen in Twin Lake near Leadville at the turn of the 20th century.

Three large Yellowfin cutthroat trout were sent to U.S. President William Henry Harrison in 1891. Photo courtesy of Sports Afield.

Townsend and Foutz along with retired CPW aquatic biologist Greg Policky – an expert on cutthroat trout with more than 30 years of experience – will embark on a search to find out. The CPW officers will spend the next few summers surveying hundreds of wetlands, streams and ponds in the upper Arkansas River basin searching for the Yellowfin, believed to be the only cutthroat native to the Arkansas River drainage.

“We are going into this search with our eyes wide open,” Foutz said. “We know the history of the Yellowfin and that it hasn’t been seen since before 1902. But millions of trout, native and nonnative, have been back and forth across Colorado since before statehood. And if the history of the Greenback and San Juan River cutthroat teach us anything, it’s that we should never stop looking.”

Map of the native ranges of cutthroat trout in Colorado. Yellowfin cutthroat were believed to be native to the Arkansas River basin; Rio Grande cutthroat are native to the Rio Grande River;  Greenback cutthroat are native to the South Platte River drainage; and Colorado River cutthroat are native to the Colorado River drainage.

CPW aquatic biologists routinely survey the state’s water to study the health of various fish populations. The quest for the Yellowfin simply broadens the scope of the annual surveys.

Both the Yellowfin and Greenback were feared lost a century ago primarily due to water pollution from mining, habitat degradation, overfishing and competition from aggressive and non-native brook, brown and rainbow trout, says CPW.

“I know how exciting it was to discover that Greenback cutthroat trout still existed in our waters,” Foutz said. “Our world is diminished anytime a species goes extinct. Searching for the Yellowfin is the fulfillment of CPW’s basic mission of perpetuating the wildlife resources of the state. Based on our recent discoveries of hidden Greenback and San Luis cutthroats, we’d be remiss if we didn’t search for the Yellowfin.”