Cutthroat trout have long been a passion of mine. They’re my favorite fish, and not because they’re easy to catch. They’re emblematic of the West, and as a fifth-generation Westerner, catching cutthroat feels like a solid connection to my unique heritage. Cutthroat face many problems, though. Habitat degradation and hybridization with rainbow trout are probably two of the biggest issues, although non-native brook trout are also excellent at outcompeting cutties for food.
A couple hundred years ago, cutthroat swam in many of the rivers and streams in the West. Thanks to our unique geography, fish considered the same subspecies—like Colorado River cutthroat, for example—can work their way up into a drainage and develop unique genetics and life histories.
For example, look at the Lahontan cutthroat in Nevada. Pyramid Lake is home to two strains of these fish. One came from Pilot Peak, on the Utah-Nevada border, and is an exact genetic match for the cutthroat that grew up to 40 pounds in Pyramid Lake back in the early 1900s. The Summit Strain Lahontan cutthroat are still Lahontans, but never grew quite as large as the original (Pilot Peak) strain.
Things can get messy the further into genetics you dig, but each subspecies of cutthroat is genetically unique, and within those subspecies and strains, the fish can vary widely in appearance and life cycles.
However, genetic diversity has allowed some cutthroat trout to persist even in the face of non-native fish, habitat loss, and reduced streamflows. The more genetic diversity we can maintain among our cutthroat trout, the better their chance of surviving for future generations.
That’s why the Hayden Creek cutthroat is so important.
Hayden Creek cutthroats are a genetically distinct strain of fish most closely related to the Colorado River cutthroat. They were first found in Hayden Creek, a tiny tributary to the Arkansas River southeast of Salida, Colorado.
“They’re a unique fish, a strain of Colorado River cutthroat trout, not the Greenback” Alex Townsend, Aquatic Biologist for the Upper Arkansas River Basin, of Colorado Parks & Wildlife (CPW) told me. “They have unique genetics that make them distinct, and they’re one of a couple cutthroat populations on the east side of the Continental Divide.”
Years ago, when the Twin Lakes area within the Upper Arkansas drainage was explored, there were two distinct populations of cutthroat trout swimming. One was the Yellowfin cutthroat, Townsend told me had a reputation for growing larger, up to six pounds. Yellowfins were primarily lake and reservoir fish, but have since gone extinct.
The other was a stream-oriented cutthroat. By comparing DNA from Hayden Creek cutthroat to museum mounts of Yellowfin cutthroat, biologists have determined that Hayden Creek cutthroat are most closely related to those original fish found in the Twin Lakes area.
Townsend said CPW biologists don’t know exactly how the Hayden Creek fish ended up there in the first place, especially since the fish they’re closely related to—cutthroat found in Twin Lakes—are now extinct.
“We’re still trying to parse out their genetics to see whether there was any anthropogenic influence or not,” Townsend said. “We can’t say for certain whether they got here naturally, but they’ve been here for as long as we know.”
Hayden Creek cutthroat were first identified as genetically unique back in 1996, and since then, biologists with CPW have searched the landscape for fish with similar genetics. To date, nothing has been found.
“I’ve been doing cutthroat surveys in unknown drainages within the Arkansas Basin, and we haven’t found anything that matches the Hayden Creek genetics,” Townsend told me. “It’s proven to be a unique fish.”
So, when the Hayden Pass fire raged in 2016, biologists knew they needed to rescue the cutthroat from Hayden Creek to ensure they persisted on the landscape. They went in behind the fire lines, rescued fish, and brought them back to a hatchery. Only 158 fish were rescued from the path of the Hayden Pass fire.
The Hayden Creek cutthroat have been successfully bred in hatcheries since then, and CPW has even stocked them in other streams within the Arkansas Basin to help restore this fish on the landscape.
The high point of this work so far was realized when biologists found young-of-the-year fish in Newlin Creek, one of the streams where Hayden Creek cutthroat have been planted in the wild. That means the Hayden Creek fish are naturally reproducing, and are capable of creating a self-sustaining population.
“Our surveys (in 2024) found ‘young-of-the-year’ fish swimming with older class fish from previous stocking,” said Paul Foutz, senior aquatic biologist for CPW’s Southeast Region. “Although this does not mean the HCC in Newlin are a self-sustaining population yet, it’s a huge step in the right direction.”
The goal now is to continue planting Hayden Creek cutthroat throughout rivers and streams in the Arkansas Basin to keep these fish persisting for years to come. To date, nearly 135,000 Hayden Creek fish have been planted in 25 miles of water and 18 ponds and lakes. Many of these fish are in places where recreational angling isn’t allowed, so Townsend is focused on creating a sport fishery for Hayden Creek cutthroat.
“I’m excited about expanding their populations, so people can go catch-and-release fish for them,” Townsend said.
Numerous sites have been selected as locations for planting these fish, including Hunt Basin, where CPW just completed a reclamation project that removed nonnative brook trout from the waters. CPW also has plans for reclamation projects in basins and lake systems on Monarch Pass, and Hayden Creek cutthroat should be planted there next year.
Virginia Lake, near Leadville, is another location where Hayden Creek fish have been stocked.
“They’re the closest thing we have to our unique native fish,” Townsend said. “The next big thing is a wild brood stock and move them out of the hatchery system.”
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