Over a 25-day stretch in April and May, Montana angler Kolton Turner hauled in a staggering 2,089 lake trout to win the 2023 Spring Mack Days fishing tournament on Flathead Lake, an hour and a half north of Missoula, Montana. In total, contestants landed $225,000 in cash and prizes while removing a total of 33,297 invasive lakers from the fishery. 

The spring event, coordinated by the Confederated Salish and Kootenai Tribes (CSKT), was the 43rd biannual running of the tournament, which started in 2002. Over 200 anglers braved spring snow, wind, and rain to participate between March 16 and May 13.

“The inception of the event came from a co-management plan that was signed in the year 2000 by the Confederated Salish and Kootenai Tribes and the state of Montana,” tournament organizer and CSKT member Cindy Benson tells Field & Stream. “That was signed after a lot of meetings and public involvement to decide how they were going to reduce the non-native lake trout in Flathead Lake and increase native fish numbers. The anglers that were at those meetings back then said, ‘If you’re going to do anything on this lake, let us be part of it.'”

Turner grew up fishing the Mack Days tournament, and he’s won the top angler prize for three consecutive years, according to Benson. The top five finishers boated a combined total of some 7,500 fish. The largest fish of the tournament weighed 36.6 pounds and measured more than 45 inches. It was caught by Bryan Long of Kalispell.

A Dual Approach to Lake Trout Suppression

Formed by glaciation at the end of the last Ice Age, Flathead Lake is the largest naturally occurring lake west of the Mississippi River. And its water is some of the cleanest and most pristine in the nation. Lake trout were introduced to the system in 1905. Since then, the non-native species has led to dramatic declines in native populations of bull trout and westslope cutthroat.

“Mack Days” draws anglers from around the state of Montana and all over the country. The tournament’s unique format allows participants to fish as many or as few days as they wish. Contestants vie for 9,000 tagged fish, which carry prizes ranging from $100 to $10,000. “They really look forward to winning some dollars off of the tagged fish,” says Benson, who hits the lake with a team of biologists the week before the event begins to tag prize-winning fish. “The ones that don’t get caught are still in the running when the fall event rolls around.”

Related: Spearfishing Team Removes Record 564 Invasive Lionfish During 2-Day Derby

According to CSKT fisheries biologist Barry Hansen, between the spring and the fall Mack Days events, the tribes remove anywhere from 50,000 and 60,000 invasive lakers from Flathead each year. The tournament is part of a two-pronged approach to lake trout suppression that also includes gillnetting. “The two strategies complement one another,” Hansen tells F&S. “The anglers can catch smaller fish more consistently than we can with nets, and they see a lot less bycatch of native bull trout than we do through our in-house gillnetting operation.”

Hansen says it’s impossible to quantify the total number of lake trout that’ve been removed from Flathead since CSKT began suppression efforts more than two decades ago, but he believes that the reduction has been substantial. “This is the largest lake in the West, and it had the largest lake trout population in the West when we began,” says Hansen. “It’s been quite a major task, but with the angling public’s help, we’re making strides.”