When Graham Knight began pulling particularly beautiful trout from Fall River where it flows beside his Clear Creek County home west of Idaho Springs, he knew he was onto something special.
Knight, an avid fly-fisherman, didn’t know quite what. Now, months later, with ice covering the small stream, he’s still not completely certain.
“I pulled out this cutthroat trout. I thought it might be a greenback, but I wasn’t sure,” said Knight, who contacted officials of the Colorado Division of Wildlife and the U.S. Fish and Wildlife Service.
Ah, a greenback cutthroat trout. Colorado’s official state fish. The immediate image is of a lovely creature, all decked out in a Sunday suit covered with large dark spots and tinged with red. What could be more glorious?
What could be more confusing?
Knight’s discovery in a highly unlikely location provides a fitting backdrop to clear up some of the confusion that continues to befuddle even veteran anglers regarding a fish that is the subject of one of the most notable back-from-the-brink endangered species success stories.
Once thought extinct, the greenback has been nourished by a couple remnant populations to reasonable health by the aforementioned agencies. More than 20 recovery sites, mostly in remote high places, have been established, with more on the way.
But over the years, a second, more prolific, culture has emerged as a product of genetic mixing, either with rainbow trout or other cutthroat, in certain places where greenbacks were being contained.
These look like greenbacks, act like greenbacks, even snack like greenbacks. But DNA testing reveals the fraud. Even though the degree of impurity is infinitesimal, these can’t be used in the recovery process.
Thus, we have what officials have termed the “recreational” greenback, a fish to be planted primarily in wild places to provide anglers with a unique opportunity. These also serve a scientific purpose of sorts.
“They help give us information on how greenbacks might survive in certain environments while providing recreation for a native Colorado fish,” said Bruce Rosenlund, who directs the recovery effort for the USFWS.
The presumption, no doubt accurate, is that anyone who has hoisted himself several thousand vertical feet up to some remote location would rather catch something that looks, and acts, like a greenback than some garden variety rainbow.
You’ll find these ersatz greenbacks in a number of locations east of the Continental Divide, where pure-strain fish can’t be completely protected from exotic incursions.
Which brings us to Knight’s discovery. While biologists are intrigued by the find, they maintain a healthy suspicion that it’s the product of recreational stocking in lakes near the Fall River headwaters.
Paul Winkle, DOW’s biologist for the area, revealed that greenback mixes have been stocked in these impoundments, notably Chinns Lake and Fall River Reservoir, starting in the early 1980s and continuing sporadically to the present.
“My gut is that they’re just fish that have come down from these lakes,” Winkle said.
Nonetheless, the biologist will attempt to capture specimens from lower Fall River when the ice melts, then subject them to the all-knowing DNA exam.
The message for high-country anglers is this: If you catch something you think is a greenback trout, put it back. It probably won’t be a genetically pure specimen, but it just might.
Besides, even the fakes are way too pretty and valuable to eat.
Charlie Meyers can be reached at 303-954-1609 or cmeyers@denverpost.com.
Greenbacks revised
The award-winning documentary on the recovery of the greenback cutthroat trout, “Incredible Journey of the Greenback Cutthroats,” has been redesigned and released in DVD format. Produced by Idledale resident Hugh Gardner for KRMA-TV, the original won nine awards at the International Wildlife Film Festival and was nominated for an Emmy for the Denver station. The re-release was made possible by a grant from Patagonia, a leader in rare trout preservation. Copies are $19.95, plus $3.50 shipping, from Western Media Products, Box 591, Denver, 80201, or the website www.media-products.com or 800-232-8902.
