Genetically unique cutthroat trout rescued from 2016 wildfire are found to be reproducing in SE Region streams

A genetically unique Hayden Creek cutthroat trout after it was rescued from a wildlife in 2016.
Photo courtesy of Colorado Parks and Wildlife

OUTDOOR COLORADO MAGAZINE

Dec. 17, 2024

CPW biologists hopeful as genetically unique cutthroat trout rescued from 2016 wildfire are found to be reproducing in SE Region streams

COALDALE, Colo. – Eight years after wildfire and flashfloods threatened to wipe out a genetically unique cutthroat trout from tiny Hayden Creek, Colorado Parks and Wildlife biologists are finding hopeful signs that their efforts to save the fish are succeeding.

Recent surveys of creeks where CPW has reintroduced the unique trout found evidence they are surviving multiple years – a huge milestone in any wildlife restoration project. Even more important, CPW biologists are finding newly hatched Hayden Creek cutthroat (HCC), meaning they are naturally reproducing in some streams and thriving.

“This is very exciting news for these fish and for the agency, considering the odds they faced back in 2016,” said Paul Foutz, senior aquatic biologist for CPW’s Southeast Region.

In July 2016, as a wildfire raged on Hayden Pass south of Coaldale, a small army of CPW aquatic biologists, hatchery staff, and U.S. Forest Service personnel donned fire-resistant suits, strapped on heavy electro-shocking backpacks, carried oxygen bottles, nets and water tanks and headed behind fire lines to pull off a daring rescue of a rare cutthroat trout from the south fork of Hayden Creek.

The dramatic effort was undertaken because massive wildfires like the Hayden Creek Fire, which charred 16,754 acres that summer, often produce ash and debris that wash into creeks and rivers, ruining water quality, choking off aquatic life and destroying habitat.

That day in 2016, CPW biologists found and removed 194 of the rare HCC trout, before the team returned to safety outside the fire zone. And their worst fears about the creek quickly came true when runoff from later rains overwhelmed Hayden Creek with a thick, black sludge that ultimately poured into the Arkansas River, damaging fish and habitat for miles in that waterway.

After the fire, surveys of Hayden Creek found no fish remained.

The only known survivors were 158 of the rare fish rescued by CPW staff and placed in an isolation unit at the Roaring Judy Hatchery near Gunnison. The other 36 had been released in nearby Newlin Creek, in the Wet Mountains about 10 miles southwest of Florence, in hopes they would survive in the wild.

Almost immediately, CPW aquatic biologists began the urgent task of finding new homes out on the landscape for the Hayden Creek cutthroat. The staff at Roaring Judy planned to keep the survivors as a brood stock and spawn new generations each spring. But they couldn’t all live in the hatchery. 

So similar sized creeks within the Arkansas River drainage were scouted. Biologists wanted creeks that were comparable in size and habitat characteristics offering year-round flow and that were remote enough to protect the prized HCC trout from human interference. 

The first creek deemed suitable was Newlin, where 36 were released during the fire. In October 2017, a team of 20 aquatic biologists, other staff and volunteers from CPW and the U.S. Forest Service (USFS) fanned out across the five drainages that make up Newlin Creek, which twists and turns through thick brush and rock in the rugged foothills.

The biologists split into six teams and bushwhacked up and down six miles, give or take, of the remote upper reaches of Newlin Creek, following the creek’s main stem and four branches. They snaked along treacherous cliffs, through jumbles of huge boulders and under fallen trees between Locke and Stull mountains.

The teams hiked for hours as the sun turned the day into short-sleeve weather, taxing some of the crew clad in rubber wading outfits and lugging 30-pound electrofishing units on their backs.

Anywhere that trickles of water pooled enough to offer fish habitat, the CPW/USFS teams stopped and probed the pools with their electrofishing units in hopes of catching a few of the 36 fish that were released during the fire.

They repeated the process dozens of times as they thrashed through the brush, scrambled over rocks, under felled trees and past caves and piles of bones from predator kills. At the end of a 10-hour marathon fish survey, the results were clear: none of the 36 HCC trout had survived.

But that day of scouting convinced the CPW team that Newlin Creek could serve as the new home for HCC trout spawned at Roaring Judy.

Biologists began the painstaking task of reclaiming Newlin of any existing fish that might compete with the HCC trout. Only then could stocking begin.

The work climaxed Oct. 24, 2018, when 900 HCC trout, each about 2 inches long, were carried in bags by CPW staff up Newlin Creek and released.

The restoration effort eventually expanded to 13 other streams across the Arkansas Drainage. Spreading them across the region makes them less vulnerable to extinction due to an isolated catastrophic fire or flood event. 

Since that first stocking in 2018, more than 8,000 HCC trout have been released in Newlin along a 1.5-mile stretch of water. After years of observing survival of the HCC trout in Newlin, CPW biologists documented evidence of natural reproduction in surveying the creek in 2024.

“Our surveys this year found ‘young-of-the-year’ fish swimming with older class fish from previous stocking,” Foutz said. “Although this does not mean the HCC in Newlin are a self-sustaining population yet, it’s a huge step in the right direction.”

To date, nearly 135,000 HCC trout have been stocked along 25 miles of water in 18 streams, ponds and lakes. These fish are produced in partnership with the U.S. Fish and Wildlife Service’s National Fish Hatchery at Leadville and CPW’s Roaring Judy hatchery.

Other streams stocked with HCC trout also show good signs of survival and multiple age classes. Those streams include South Ruxton Creek on Pikes Peak near Colorado Springs, South Middle Creek near La Veta Pass west of Walsenburg, and Iowa Gulch near Leadville in the Upper Arkansas Valley. 

It was stocked with HCC trout from 2021-24 with roughly 5,000 fingerlings a year. A 2024 survey found evidence of natural reproduction as over 20 young-of-the-year fish were found before fall stocking had occurred. Also, two fish up to 12 inches long were sampled, which shows great growth potential.

“CPW’s mission begins with a vow to perpetuate the wildlife resources of Colorado and this is a perfect example,” said Foutz, who was on the CPW team that rescued the Hayden Creek cutthroat from the wildlife in 2016. “These fish have unique genetics and it’s our job to ensure they remain on the landscape for future generations of Coloradans.”

CPW aquatic biologists and hatchery staff deeply involved in the HCC restoration are Carrie Tucker in Pueblo, Alex Townsend in Salida, Cory Noble in Colorado Springs, and CPW Hatchery Manager Seth Firestone and hatchery crew, and USFWS Hatchery Manager Josh Homer. 

Watch the fish survey work on Newlin Creek in October 2017: https://www.youtube.com/watch?v=1SjhrQpwib4&feature=youtu.be.