Leadville Fish Hatchery a window on Colorado’s past and future
Summit County correspondent
Aspen, CO Colorado
LEADVILLE, Colo. – As Colorado’s state fish, the greenback cutthroat trout is a symbol of the Rocky Mountains’ natural splendor. The strikingly speckled, red-throated native fish calls to mind the sparkling high-alpine streams and lakes where the trout makes its home along the Continental Divide.
However, just a few decades ago, few would have guessed the greenback cutthroat (Oncorhynchus clarki somias) would come to represent Colorado’s wild landscapes. As recently as 1970, the fish was considered to have been extinct for almost half a century.
The greenback – a relatively small member of the trout, salmon and whitefish family – is the only trout endemic to Colorado’s South Platte and Arkansas River drainages. The fish favors the icy, clear waters and rocky bottoms of headwaters streams, where it finds its meals of crustaceans, insects and small fish. Greenback cutthroats once thrived in those waters, but by the late 1800s, white settlers had taken a serious toll in a variety of ways: overfishing; dams; pollution from mining and agriculture; logging; and introduction of competing species.
“The whole intermountain region was being depleted of resources, including fish resources,” said Ed Stege, project manager of the Leadville National Fish Hatchery, a facility of the U.S. Fish and Wildlife Service. “Leadville had 30,000 miners and supporting cast members. Back then, there weren’t a lot of regulations.”
The federal government became concerned with population declines in the region’s rivers and streams and became determined to revive game fish for human consumption. In 1889, Congress established the Leadville National Fish Hatchery in Lake County on the eastern flank of Mount Massive. With $15,000 in federal funding, a regal, red-sandstone Victorian building was erected to house fish-rearing activities.
“This was considered one of the more picturesque buildings in Colorado,” Stege said.
The facility is the country’s second-oldest federal fish hatchery, and still operates today – albeit in a more ecologically sensitive manner than it did in the 1890s.
“Early fish hatcheries were the Johnny Appleseeds of the fish world,” Stege said. “They just moved fish all over the place.”
Brook trout, rainbow trout, lake trout, brown trout and Atlantic salmon – none of which are native to Colorado – were introduced into the region’s waters in great numbers. (For much of the 20th century, the rainbow trout was the unofficial state fish of Colorado, even though the species is native to the American West Coast.) Unfortunately for the native cutthroats, they are much more difficult to cultivate in captivity than their nonnative trout cousins are.
“Back then, people were interested in cultivating fish that grew well,” Stege said.
The nonnative species competed for food and habitat with the indigenous and already-imperiled greenback cutthroat. Furthermore, rainbow trout and non-native subspecies of cutthroat are capable of breeding with greenbacks, thereby diluting the native fish’s gene pool.
The Leadville Hatchery’s reach extended far beyond the Rocky Mountain region. Fish and eggs were transported by horse, ship and train to other states and places as far away as Japan and Germany.
By the early 1900s, greenbacks were nearly absent from their native range, and the subspecies was considered extinct in 1937. Luckily, in 1973 – the same year the U.S. government enacted the Endangered Species Act – two small populations of greenback cutthroat trout were discovered in the headwaters of the South Platte. The populations totaled less than 2,000 individuals and covered 2.9 miles of stream habitat. Subsequently, seven additional small populations were discovered on other stream stretches, including in the Arkansas River headwaters. The greenback cutthroat was listed as a federally endangered species, and recovery efforts have produced promising improvements. In 1978, the fish’s conservation status was downgraded from “endangered” to “threatened.” However, according to the Colorado Division of Wildlife, the fish can be found today throughout only about 5 percent of its estimated original range. The greenback cutthroat was named Colorado’s official state fish in 1994.
Today, the Leadville National Fish Hatchery is a key player in a team of state and federal agencies working toward the greenback cutthroat’s recovery. Inside the building, Stege is developing cultivation techniques to rear the fish for eventual release into native waters. The indoor concrete tanks house thousands of young fish destined for the cold, clear streams their ancestors once swam. For the last three years, the facility has stocked greenbacks in Lily Lake, inside Rocky Mountain National Park.
Outdoors, larger concrete tanks called “raceways,” built in the 1950s, hold rainbow trout and other species used for stocking in the state’s reservoirs, lakes and rivers to support recreational fishing. Each year, the Leadville Hatchery produces 170,000 to 200,000 game fish for distribution to waters on federal and state lands. But today, such stocking efforts are conducted with sensitivity to the recovery of the greenback cutthroat.
“There’s still a lot of attention paid to not stocking brook trout in high mountain streams and figuring out how to remove them,” Stege said.
The U.S. Fish and Wildlife Service works cooperatively with state wildlife officials to develop distribution plans, carried out by fish-distribution trucks, each of which are capable of transporting thousands of fish at a time. First priority is given to waters on federal lands, including military installations, Indian reservations and national parks. Waters under state control, including Dillon Reservoir and Silverthorne’s North Pond, are next in line.