SALIDA, Colo. (KDVR) – A species previously believed long gone may once again emerge from Colorado’s waterways, further proving that “zombie” isn’t a term that can only be applied to human reanimation.

In recent years, the Greenback and San Juan River cutthroat trout species that were declared extinct have been found in various bodies of water by Colorado Parks and Wildlife officials.

Now, with these revelations in mind, officials at CPW are wondering whether or not other species on that list of animals long gone may still be among us.

The potential existence of the extinct yellowfin cutthroat trout, a fish breed that was discovered in July of 1889 by David Starr Jordan and G. R. Fisher in the Twin Lakes near Leadville, is now being pondered upon by wildlife experts across the Centennial State.

Three of those individuals have taken that brainstorming one step further and are now leading the mission to get yellowfin cutthroat trout onto the zombie fish list, which consists of species that have returned from extinction.

The search for yellowfin cutthroat trout

“Searching for the yellowfin is the fulfillment of CPW’s basic mission of perpetuating the wildlife resources of the state,” CPW’s Paul Foutz said. “Based on our recent discoveries of hidden Greenback and San Luis cutthroats, we’d be remiss if we didn’t search for the yellowfin.” 

Over the next few summers, CPW aquatic biologist Alex Townsend, CPW Southeast Region senior aquatic biologist Paul Foutz and retired CPW aquatic biologist Greg Policky will be roaming through the Arkansas River Basin in search of the only trout species that used to be found there.

CPW said that the region has a large number of streams, lakes, gulches and other bodies of water that have either hardly been sampled, or haven’t been sampled at all. With the help of a team of aquatic biology technicians, Policky and Townsend started sampling near Twin Lakes this month.

“This is a very exciting opportunity to explore these uncharted waters in search of the yellowfin,” Policky said. “I dedicated my career to learning everything possible about these fish and I’m honored to be part of the CPW team conducting this search.” 

Through the use of electro-fish, net and the simple hook-and-line method, crews will acquire tissue samples from the trout they find there to analyze their genetic makeup to see if it matches that of the yellowfin cutthroat trout.

The sampling scheduled for the subsequent summers of 2023, 2024 and 2025 will all be performed by a separate crew so they can gather autonomous data that isn’t influenced by this year’s results.

The history of yellowfin cutthroat trout

Yellowfins, according to their initial discoverer David Starr Jordan, carried an average weight of 10 to 12 pounds and were typically lake specialists.

Propagated in Leadville National Fish Hatchery between 1892 and 1905, yellowfins were transferred into lakes across Colorado. Something that may have led to the yellowfin’s disappearance was the introduction of nonnative fish that may have cross-bred and diluted the now presumed extinct species’ bloodline.

According to the U.S. Fish and Wildlife Service, between 1889 and 1925, over 50 million cutthroat trout from the Gunnison and White River Basin were brought to Colorado’s lakes. Also, from 1914 to 1925, the state fish commission introduced 26 million cutthroats to the state’s waterways.

Nowadays, one of the seven original yellowfin specimens found by Jordan and Everman back in 1889 sits in the Smithsonian Museum of Natural History in the nation’s Capitol.

Wildlife enthusiasts everywhere wait to see if the efforts heralded by Townsend, Policky and Foutz with CPW will find that specimen’s ancestors.