Glacier proposes to remove non-native fish from Gunsight Lake

Glacier National Park is looking for public comment on a proposed plan to use fish poison to remove non-native rainbow trout from Gunsight Lake.

The plan is part of an effort to protect and establish secure populations of native westslope cutthroat trout and bull trout. Native westslope cutthroat trout — a state-listed species of concern — in the St. Mary River drainage on the east side of Glacier National Park are at risk from hybridization with non-native fish.

The St. Mary River drainage also supports bull trout, which are listed as threatened under the Endangered Species Act, and is the only drainage in the United States where bull trout are found east of the Continental Divide.

The plan proposes the use of fish toxicant to remove the non-native rainbow trout from Gunsight Lake followed by the translocation of bull trout and genetically pure westslope cutthroat trout into the lake afterwards.

Historically fishless, Gunsight Lake was stocked with non-native fish in 1916 and between 1920 and 1936. The stocking included rainbow trout, which can migrate downstream and hybridize with native westslope cutthroat trout. The lake is well positioned to provide secure habitat for native fish as downstream waterfalls block upstream non-native fish migration.

In 2019, Glacier National Park in partnership with Montana Fish, Wildlife and Parks, the U.S. Fish and Wildlife Service, and the Glacier National Park Conservancy undertook a similar project in the Camas Creek drainage. The effort saw the successful removal of non-native Yellowstone cutthroat trout from Camas and Evangeline lakes and the translocating of native westslope cutthroat trout and bull trout to both lakes.

The plan remains only an initial proposal. No decision to implement any action can be made until the National Environmental Policy Act process, which includes consideration of reasonable alternatives to the proposed action, is complete.

Public scoping is being conducted to identify issues, concerns and other alternatives to evaluate in the environmental assessment. There will be another opportunity for public comment when the assessment is completed.

More information on the proposed project may be found on the NPS Planning, Environment, and Public Comment (PEPC) website.

Comments can be posted on the PEPC site or sent by mail to Superintendent, Glacier National Park, Attn: Gunsight Lake EA, PO Box 128, West Glacier, MT, 59936.

Comments are due by Oct. 26.

Reporter Jeremy Weber can be reached at jweber@dailyinterlake.com.