Restoring Flow and Fish Passage at Sager Lane

In September 2024, we began work to remove a century-old “pin and plank” irrigation diversion just upstream of Sager Lane near Deer Lodge. This structure stretched across the entire Clark Fork River, blocking fish passage, creating safety hazards for boaters, and reducing the river’s natural flow. It was the fifth in a series of eight planned upgrades to outdated irrigation dams along the mainstem of the Clark Fork River.

Until recently, this diversion was a significant barrier for native fish trying to migrate upstream and for recreational users floating the Upper Clark Fork River. Thanks to the removal of the dam—and the installation of new rock weirs, riprap, and irrigation infrastructure—this stretch of river is now flowing freely once again. The upgrades not only improve fish habitat and migration, but also maintain reliable irrigation for local landowners. A win-win for people and wildlife.

Work is continuing and includes riverbank reconstruction, native revegetation, and the removal of contaminated sediments. These improvements will boost overall river health and increase in-stream flows, supporting a more resilient river system.

This important restoration project was made possible with support from the Natural Resource Damage Program, Montana Fish, Wildlife & Parks’ Future Fisheries Program, Trout Unlimited’s Clark Fork River Project, Resources Legacy Fund, Tetra Tech, Intermountain Construction Services, Watson Irrigation, and the generous cooperation of local landowners.