FWP moves to remove illegally stocked bass from Livingston’s Sacajawea Lagoon

Montana Fish, Wildlife and Parks wants the bass out of Sacajawea Lagoon in Livingston before they reach the upper Yellowstone. An environmental assessment posted Sept. 17, 2026, says the department got smallmouth reports in late May. On June 1, electrofishing caught six largemouth of 11–12 inches and three smallmouth of 10–13 inches. FWP calls the introductions illegal. A culvert at the inlet connects to the Yellowstone, and the outlet can send fish down Fleshman Creek.

The plan is to dewater the lagoon. A barrier where Fleshman Creek enters would send water toward the Yellowstone. The outlet would be screened, then check boards pulled over several days so the drain does not blow out banks in the neighborhood downstream. That would dry about a mile of Fleshman Creek. A spring near M Street should keep some flow to the river. Staff would move fish from the dried reach to below that spring, euthanize fish taken from the lagoon, and restock Yellowstone cutthroat.

The agency notice sets the work window at Dec. 11, 2026, through June 31, 2027. Montana Outdoor, carrying Brett French’s Oct. 2 Billings Gazette report, corrected that end date to June 30, because June has 30 days. Written comments were open from Sept. 17 through Oct. 2 to Scott Opitz at sopitz@mt.gov, or by mail to 6 Church Drive, Livingston, MT 59047.

This is a The Gillnet news desk summary, not a reprint.

Source: Montana FWP — Sacajawea Lagoon bass removal EA (Sept. 17, 2026). Also: Montana Outdoor — Bass illegally stocked in Livingston pond (Oct. 2, 2026).