Although the greenback cutthroat trout Oncorhynchus clarki stomias has been the focus of conservation efforts for more than half a century—starting when the once-lost species was “rediscovered” in a remote part of Rocky Mountain National Park—genetic research over the last decade has produced some blockbuster findings that threw all previous work into question. It turns out that many of the fish that both state biologists and anglers had considered greenbacks were, in fact, not greenbacks at all. As a result, many fishermen who had added the species to their life lists had to cross it off, and it looks to be some time before any of us will be able to catch a wild, pure greenback again. Luckily both public and private efforts to restore the species to its native range are gaining momentum.
The Accidental Preservationist
We owe the modern existence of pure-strain greenbacks to an unlikely source: an entrepreneurial homesteader named Joseph C. Jones. In 1873, a trail to the top of Pike’s Peak was constructed along Bear Creek, and Jones established a homestead there. Since the hike to the summit took two days, Jones thought he would build a hotel and restaurant to cater to the travelers. Researchers believe that Jones stocked the pure greenbacks in Bear Creek to provide recreation and food for his guests, although where he got the trout remains a mystery. Because the upper part of the creek is separated from its lower reaches by a barrier, the greenbacks were protected from hybridization and were able to survive, undisturbed for the next 130 years. These fish are now the genetic source of all future populations.
Plans for the Future
When the trout of Bear Creek were identified as the only known population of greenbacks, efforts to protect and restore the species kicked in quickly. In 2006, Colorado Parks and Wildlife closed Bear Creek to fishing, and bans on camping and fires soon followed. In 2008, about 10 percent of the creek’s trout were moved to a state hatchery in Salida to start a brood stock and to serve as a backup if disaster struck Bear Creek. On August 8, 2014, the first release of hatchery-reared, genetically pure greenbacks occurred at Zimmerman Lake, west of Fort Collins, which had been rendered fishless in anticipation of the stocking. Those fish should be ready to spawn in two years, which will be the first step in a long recovery process. The goal is to establish stable populations throughout the South Platte Basin—hopefully a new population each year for at least the next five-year period. Last fall, state fisheries biologists began reintroducing greenbacks to rivers along the Front Range.
Range and Species History
According to the latest thinking, the original range of the greenback cutthroat trout was limited to the South Platte Basin of eastern Colorado. Previously, it was believed that the species also lived in the Arkansas River drainage, but the new genetic evidence suggests otherwise. Writing in 1891, David Starr Jordan was the first to use the name “greenback” to describe the species, which he also referred to as the “trout of the Platte.”
A combination of habitat loss, pollution, and hybridization caused a rapid decline in the greenback population throughout the late 1800s and into the next century. By 1937, the native greenback cutthroat was declared extinct.
Twenty years later, fish believed to be pure-strain greenbacks were discovered in remote waters of Rocky Mountain National Park, but there were very few of them. When the Endangered Species Act was passed, in 1973, the greenback was on the first-ever list of endangered species. As more populations were identified in the 70s, the species’ status was downgraded to “threatened”—which meant that anglers could legally catch them—and state and federal agencies began restoring them to more waters by raising these supposedly pure greenbacks in hatcheries and then stocking them. By the late 90s, the fish could be found in 62 different locations and were ready to be de-listed. . .until science interfered.
In 1999, new genetic studies revealed that the fish being used as brood stock were not, in fact, pure greenbacks. So the biologists were forced to start over, using what they believed to be non-hybridized greenbacks. But in 2007, research at the University of Colorado-Boulder showed that, again, they’d been saving the wrong fish. According to the most advanced genetic data, the true greenbacks lived in just one four-mile stretch of Bear Creek south of Pike’s Peak and there were only about 700 of them left. Because of their singular appearance, these fish had been deemed too “weird” to be used as brood stock in earlier efforts. Their weirdness turned out to be a sign of uniqueness.
There are now thousands more greenbacks in the Leadville National Fish Hatchery and the Poudre State Hatchery—representing the pioneering fish of the next round of recovery work.
The Listing Problem
Currently, greenback cutthroat trout are still listed as “threatened,” and pretty much everyone involved in Colorado would like to see them stay that way. If the species were to be declared “endangered,” many different kinds of outdoor recreation would be affected. A change in status for the greenback would set limits on state management and restrictions on angling. To avoid that, the greenback recovery team aims to show that populations are on an upward trajectory, so “endangered” status is unnecessary. Until greenback populations have been established in more waters, protection of the Bear Creek population, from siltation and runoff from trails, is in everyone’s best interest.
Special thanks to Doug Krieger of Colorado Parks and Wildlife for his help with this article. Click here to see Joe Tomelleri’s beautiful illustration of a Bear Creek greenback.