There's No Longer A Doubt About This Cutthroat Trout

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It's been a cutthroat existence for Colorado's state fish.

The rare greenback cutthroat trout, for years on the receiving end of a well-meaning, but taxonomically misguided attempt to save it, now seems to be back on track (though not out of the woods).

Two years ago, wildlife biologists confirmed through genetic testing that for decades they'd been restocking Colorado's lakes and streams with the wrong fish, reports Stephanie Paige Ogburn of member station KUNC.

She writes: "The mix up was understandable — different subspecies of cutthroats are hard to tell apart." Suspicion was raised in 2007, and five years later, genetic testing done at the University of Colorado, Boulder confirmed the case of mistaken identity.

In 1937, the greenback cutthroats were thought to have gone the way of the passenger pigeon, "victims of mining pollution, fishing pressure and competition from other trout species," Science Daily reports.

Rumors of the greenback's demise ultimately proved to be exaggerated — small populations were discovered in the Arkansas River and South Platte River drainages in the 1950s, and biologists set about using them as breeding stock to boost the fortunes of the state fish elsewhere.

But it turns out they were using close relatives of the greenback, not the state fish itself. The only authentic population of greenbacks still in existence was found in Bear Creek, a tiny tributary of the Arkansas River west of Colorado Springs.

"We've known for some time that the trout in Bear Creek were unique," Doug Krieger, senior aquatic biologist for Colorado Parks and Wildlife, was quoted by The Denver Post as saying. "But we didn't realize they were the only surviving greenback population."

In this video from 2012, Krieger explains that the trout species isn't native to Bear Creek but was introduced in the 1870s or 1880s by a businessman hoping to cash in on the cutthroat.

"It was a popular trail up to Pike's Peak at the time and he wanted to have an inn for the people who were on that two-day journey," Krieger says. "In doing so, he also created some fish ponds and brought in some fish most likely from Trout Creek, which [was] one of the closest trout streams to Colorado Springs at the time."