Small lake trout eat Kokanee salmon, rainbows, and cutthroat trout in addition to lake trout eggs.

A new — and hopefully annual — event at Flaming Gorge Reservoir has its debut this weekend. The “Mac Attack” Derby will be held April 26-28. Sponsored in part by the Flaming Gorge Chamber of Commerce, the Wyoming Game and Fish Department and the Utah Division of Wildlife Resources, a unique format promises the potential great lake trout action with the added benefit of thinning the population of pups in the world-class fishery.

A two-man team event, each team can weigh up to 24 lake trout per day with each lake trout measuring less than 25 inches in length. Culling, will not be allowed which means that when a fish is caught the participants must immediately decide whether to release the fish or put it into their ice box to be eventually weighed.

The entry fee is $100 per team and registration will take place from 8:30 a.m. to 5 p.m. on Friday, April 26 in the following locations: Flaming Gorge Market and Lucerne Marina (Manila), and the Green River and Rock Springs Chambers of Commerce.

Why should they hold such an event?

You don’t have to look too far to see that fishery managers from Utah and Wyoming are concerned that there are too many small lake trout in Flaming Gorge. For many years, anglers and wildlife officials alike have noted a steady increase of fish under 25 inches.

Although the fish are fun to catch and eat, large numbers of small lake trout create problems for growing trophy-sized fish.

Rob Keith, regional fisheries supervisor for the Wyoming Game and Fish Department recently said, “Our 2016 studies showed that due to the abundance of lake trout, their growth rates have slowed dramatically. In 1992, an 8-year-old lake trout was 31 inches (in length) and (weighed) over 10 pounds. In 2016 we found that eight-year-old lake trout were 22 inches (long) and (weighed) about three pounds.”

When burbot were found in the reservoir, officials warned they would feast on the eggs of spawning lake trout and severely curtail reproduction. However, when fishing spawning beds in the fall, I routinely catch both burbot and pup lake trout, their mouths absolutely stuffed with freshly deposited lake trout eggs. I see very little difference between burbot feeding on the eggs and small non-spawning lake trout gobbling up the eggs.

Besides feeding on spawning beds, smaller lake trout also prey on rainbows, cutthroats, and kokanee salmon which is problematic for maintaining healthy populations of those species. In a recent trip, I fished from the shore in the Lucerne Bay area of Flaming Gorge and caught a good number of rainbows with a very typical presentation, small green or white tubes tipped with a piece of night crawler. Instead of catching only rainbows, I caught several 17- to 22-inch lake trout that were literally feeding in the same school as my target species.

To protect the fishery and to educate anglers as to the importance of population balances, especially when attempting to manage a trophy reservoir such as Flaming Gorge, officials believe holding this derby is at least one step towards improving conditions for growing larger fish.

“Flaming Gorge is well known as a place where one can expect to catch a 30- or 40-pound lake trout any time you get out”, says Mark Wilson, president of the Flaming Gorge Chamber of Commerce. “And fishery managers know there are record-setting 50-plus pound fish (still) out there. We hope this effort will continue to produce more of these lunkers for years to come.”

“Angler harvest is a highly effective tool for managing fisheries,” said Ryan Mosely, Flaming Gorge project leader for the Utah Division of Wildlife Resources. “Creating a new derby helps us reduce the small lake trout population, educate the public on this growing concern, and allows anglers to go out and have fun doing it.”

For more information, including the rules for the “Mac Attack,” call the Dutch John Office of the UDWR: 435-885-3164 or online at