Jon Roanhaus / Wikimedia Commons
Fisheries managers in Wyoming and Utah are betting that anglers will help solve a growing ecological imbalance at Flaming Gorge Reservoir, where an expanding population of lake trout is threatening the kokanee salmon that draw sportfishing visitors to the southwestern Wyoming destination.
Why It Matters
Kokanee salmon populations at Flaming Gorge have been falling even as wildlife agencies have ramped up stocking efforts. Meanwhile, smaller lake trout — nonnative predators that feed on juvenile kokanee — have multiplied in the reservoir. The question now is whether lifting harvest restrictions will be enough to turn the tide, and whether enough anglers will participate to make a difference.
What Happened
In late 2024, Wyoming and Utah wildlife agencies reclassified lake trout at Flaming Gorge as a nongame species, eliminating the harvest limit for fish under 28 inches. Prior to that change, anglers were allowed to keep 12 lake trout per day, with no more than one exceeding 28 inches. That daily limit had itself been raised from eight fish sometime in the early 2000s.
Fisheries managers divide the lake trout population into three informal size categories: fish under 17 inches are called “puppies,” those between 17 and 28 inches are called “pups,” and fish over 28 inches are considered trophies. The new rules leave trophy-sized fish protected under a one-per-day cap, while the smaller and mid-sized fish can now be harvested without restriction.
The Flaming Gorge Chamber launched a program offering payment for lake trout heads as an additional incentive to encourage removal of the fish from the reservoir.
Condition of the Fish
Scientific analysis of lake trout otoliths — the small bones used to determine fish age — revealed that growth rates have slowed considerably. John Walrath, the current Green River Region fisheries supervisor for Wyoming Game and Fish, described the fish as appearing aged and underweight, saying they were “just not in good condition.” The findings point to an overpopulated predator class competing heavily for limited food resources.
While trophy-sized lake trout numbers have declined, the population of smaller fish has grown — a pattern consistent with a stunted, overcrowded population consuming the very prey species, like kokanee, that the reservoir’s recreational fishery depends on.
Boots on the Ground
Robb Keith, a Wyoming Game and Fish retiree who supervised the Flaming Gorge fishery for 25 years and began the agency’s outreach campaign on lake trout management in 2003, has remained personally involved in addressing the problem. By April 30, 2026, Keith had personally caught and removed more than 455 juvenile lake trout from the reservoir. He acknowledged the scale of the challenge, saying, “Really, it’s one fish at a time to try to reduce their numbers.”
By the Numbers
- Late 2024: Lake trout under 28 inches reclassified as nongame with no harvest limit
- 2019: Daily lake trout limit raised to 12 fish (one over 28 inches allowed)
- Early 2000s: Daily limit raised from an earlier cap to 8 fish
- 455+ juvenile lake trout removed by Robb Keith through April 30, 2026
- 25 years: Keith’s tenure managing the Flaming Gorge fishery
Zoom Out
Flaming Gorge is far from alone in facing this problem. Lake trout have created similar disruptions for native and stocked fisheries at Yellowstone Lake, Idaho’s Lake Pend Oreille, and Colorado’s Blue Mesa Reservoir. In some of those cases, fisheries managers have moved beyond encouraging recreational harvest, turning to angler payment programs and commercial fishing crews to accelerate population control. The pattern across the Mountain West suggests that voluntary angler participation alone may be insufficient without additional intervention.
The challenge at Flaming Gorge also fits into a broader conservation picture in the region. Wyoming wildlife managers have been navigating multiple long-term habitat and species management efforts across the state, including a decades-long effort to formally protect the Path of the Pronghorn migration corridor that is nearing completion.
What’s Next
Whether the unlimited harvest policy will meaningfully reduce lake trout numbers depends largely on angler participation. Fisheries managers are continuing stocking efforts for kokanee while monitoring whether the new regulations and bounty program drive increased harvest of smaller lake trout. The coming seasons will offer early data on whether the strategy is gaining traction.
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