Missoula restores McKinley Lake and unveils model to remove six more wilderness dams

The City of Missoula has completed a pilot dam decommissioning at McKinley Lake designed to return a constricted reservoir to its historic footprint and restore stream and fish habitat, city ecosystem services lead Morgan Valiant told a Rattlesnake Creek Watershed Group presentation. Valiant described multiyear planning, engineering, controlled blasting and hand restoration that produced a functional stream channel and a recovering riparian area.

Valiant said McKinley was selected as a pilot because of a head‑cut erosion scar and seepage threatening dam integrity, modest storage (quoted in the presentation as about 168 acre‑feet) and detailed historic engineering records that simplified design. "We picked McKinley Lake," he said, "so the rest of this talk I'm going to really be focusing on the work we've done up at McKinley." He told the audience the team rebuilt roughly 1,500 feet of stream, installed about 15,000 native plants and 10,000 willow cuttings, and leveraged volunteers to complete much of the work.

Why it matters: the McKinley project demonstrates a repeatable approach to aging dams on federal wilderness lands where the City of Missoula holds water‑storage rights. Valiant said the removal work and channel reconstruction reconnected fish…