Colorado State Fish: Greenback Cutthroat Trout

Dec 12, 2023 | 3 minute read
Reading Time: 3 minutes

The clear waters of Colorado‘s streams and rivers are home to several different types of Trout. Brook, Rainbow, and Brown Trout inhabit these waters in a large number. However, none of them is the official state fish of Colorado. How come?

Sunset over the river creek in Colorado
The creeks of Colorado are home to many different Trout species.

Well, the Centennial State chose a different kind of freshwater warrior to represent them. The official state fish of Colorado is the infamous Greenback Cutthroat Trout. This beautiful, feisty Trout was thought to be extinct in the 1930s. However, to the surprise of Coloradans, the fish made a strong comeback in the 1960s – or did it?

The Unusual Story About Saving the Colorado State Fish

Following its unusual reappearance, the Greenback Cutthroat Trout united many people around a large conservation effort. In 1973, the fish was listed as endangered. That’s when the effort to rebuild the population became massive and lasted over the course of 40 years. This resulted in the Greenback Cutthroat Trout becoming Colorado state fish in 1994.

The conservation efforts progressed and, for many years, it seemed that the plan was working very well and that the species was not endangered anymore. Unfortunately, that was not the case.

In 2012, a research team from the University of Colorado Boulder found out that the U. S. Fish and Wildlife Service and Trout Unlimited have been trying to save the wrong fish. It turned out that the fish they were restocking wasn’t the Greenback Cutthroat Trout, but its cousin! Millions of dollars had been spent to save a different kind of Cutthroat Trout – native to the Western Slope – and it spread through the rivers of the Front Range at a massive rate.

The research showed that the cause of the mix-up was a preserved sample from the 1850s. This sample was wrongly marked as coming from the South Platte River, but it is far more likely that the sample actually came from the Rio Grande.

Even though this mistake could have resulted in the Greenback Cutthroat Trout becoming extinct, a surprising discovery changed the narrative of this story. In a remote tributary of the Arkansas River, in a four-mile area of Bear Creek, the researchers found the only surviving wild population of the Greenback Cutthroat Trout!

The Fight for Survival

Many have wondered how the fish ended up here, and how it survived. The population found in Bear Creek was the result of the stocking efforts of a homesteader, J. C. Jones, in the 1870s. J. C. was planning to build a hotel near Bear Creek. He stocked the ponds with fish taken from the streams in the South Platte River Basin. No other Trouts lived in the creek, and that’s why the Greenback Cutthroat Trout managed to survive here for more than 150 years!

Today, the species is still threatened, with many conservation efforts taking place all around the state.

What Does the Greenback Cutthroat Trout Look Like?

A picture of the Colorado State Fish, the Greenback Cutthroat Trout, taken from side with rocks behind the fish
Courtesy of Colorado Parks and Wildlife

The Greenback Cutthroat Trout can grow up to 18 inches long, and grow as large as 10 pounds. Compared to other Cutthroats, Greenbacks have the largest black spots all over their bodies and tails. Their bellies turn red or orange during the spawning season – in spring and early summer. They can live up to five years old in smaller rivers, and up to ten years old in lakes.

And that’s how the unusual story of the Greenback Cutthroat Trout goes – so far! These creatures have lived to fight another day, and we hope to see plenty more of them (and their cousins) all across Colorado for generations to come.

Have you ever seen a Greenback Cutthroat Trout? Do you know any other cool facts about this fish that we haven’t included in the article? Let us know in the comments below!

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