Please purchase a subscription to read our premium content. If you have a subscription, please log in or sign up for an account on our website to continue.

Please log in, or sign up for a new account to continue reading.

Thank you for reading! We hope that you continue to enjoy our free content.

Welcome! We hope that you enjoy our free content.

Thank you for reading! On your next view you will be asked to log in to your subscriber account or create an account and subscribe purchase a subscription to continue reading.

Thank you for reading! On your next view you will be asked to log in to your subscriber account or create an account and subscribe purchase a subscription to continue reading.

Thank you for signing in! We hope that you continue to enjoy our free content.

Please log in, or sign up for a new account and purchase a subscription to continue reading.

Please purchase a subscription to continue reading.

Your current subscription does not provide access to this content.

Sorry, no promotional deals were found matching that code.

Promotional Rates were found for your code.

Sunshine and clouds mixed. High 52F. Winds SE at 15 to 25 mph, becoming WNW and decreasing to 5 to 10 mph. Winds could occasionally gust over 40 mph.

Partly to mostly cloudy. Low 18F. Winds NW at 5 to 10 mph.

Mostly cloudy skies. High 26F. Winds NNW at 5 to 10 mph.

YELLOWSTONE LAKE — By mid-October there was little sign of life at Bridge Bay Marina on the northwest corner of Yellowstone Lake. The fleet of fishing boats had been trailered away, the parking lot empty, the bathrooms locked. But nobody had wiped the whiteboard clean.

A marked-up map just outside the staging area for an immense ecosystem restoration project showed where crews set nets. A tally left on the board from early September counted 204,300 slain exotic lake trout from the summer. By the time Yellowstone National Park’s lead fisheries biologist, Todd Koel, talked to WyoFile a month after the last whiteboard update, the cull had jumped by an additional 80,000 fish.

Another year, another big haul of exotic char netted from 136-square-mile Yellowstone Lake.

This was not the game plan.

Back in 2012, Yellowstone officials announced that after a decade of underestimating the nonnative fish, also known as mackinaw — which proliferated at the expense of native cutthroat trout — they’d finally scaled up their netting operations to a degree that would meaningfully drive down the lake trout population. By stringing up to 6,000 miles of gillnet throughout the big lake over the ice-free months, Koel and his crews sought to catch and kill half of all the lake trout dwelling in Yellowstone Lake every single year.

At an expense of $2-3 million a year, they’ve succeeded on some fronts: More than 80% of mature, fish-eating lake trout have been eliminated, and there are anecdotal reports of some spawning cutthroat trout staging a comeback. The end goal was always causing a population crash. Models suggested a collapse would happen and the National Park Service narrative was that, after a sharp decline, Yellowstone could back off netting and turn to a less intensive and costly “population maintenance” method, like killing mackinaw eggs in spawning bed cobbles.

But numbers of young lake trout have stayed high even after 11 straight summers of intensive netting. Koel now questions if that precipitous crash will ever come.

“Into the foreseeable future, gillnetting is always going to be the cornerstone of suppression,” Koel said. “There is a component of it that will become more long-term operational, just like we maintain roads and do other maintenance.”

Netting, he said, is “just going to be a part of” Yellowstone.

It’s not entirely settled how lake trout arrived in Yellowstone Lake, but the most accepted theory is that an angler caught some in nearby Lewis Lake, kept them alive in a livewell or bucket and drove down the highway to release them. At the time of lake trout’s 1994 discovery, Yellowstone Superintendent Bob Barbee called it “an appalling act of environmental vandalism.”

Koel has since posed an alternative theory: lake trout washed out of Jackson Lake and swam to Yellowstone Lake on their own, heading up Pacific Creek and down Atlantic Creek by crossing over the Continental Divide at the “Parting of the Waters.”

Regardless of how they got there, the fish-eating char from the Great Lakes and Canada thrived. Within a couple decades, by 2012, there were nearly a million of them, according to Koel. Before lake trout, Yellowstone Lake was arguably the flagship cutthroat trout fishery on planet Earth, but as predation from the larger piscivore ramped up, the native trout population plummeted. The resulting story of ecological collapse is one for the history books: Researchers even drew lines from spawning cutthroats’ absence in Yellowstone Lake tributaries to higher grizzly bear predation on elk calves.

Yellowstone started taking the invasive trout more seriously and ramped up its killing program upon a change of administration. The shift came in 2011, when Dan Wenk replaced retiring Suzanne Lewis as superintendent.

“Dan Wenk said, ‘This is not going to happen, we’re not going to have this environmental disaster on my watch,’’” recalled Cody resident Dave Sweet, a Trout Unlimited volunteer who’s been a longtime spokesman and fundraiser for the Yellowstone Lake cutthroat restoration program.

Under the new regime Yellowstone and its nongovernmental partners started sinking millions of dollars annually into its netting program.

WyoFile is an independent nonprofit news organization focused on Wyoming people, places and policy. This story was edited for space. The full story can be found in its entirety at wyofile.com.