Eustache Creek Mine Reclamation

Placer mine tailings

Eustache Creek is a headwater tributary (2nd order) of Ninemile Creek, which flows into the Clark Fork River approximately 25 miles west of Missoula, Montana.  Located in the Lolo National Forest, the Ninemile Creek watershed was severely impacted by sporadic placer mining activity in the early 1900’s and never restored to a natural condition.    In Eustache Creek alone, over 1.3 miles of damaged stream pose risks to long-term channel stability, fish recovery, and the health of the watershed downstream.

Specific problems in Eustache Creek include piles of dredged material (gravel, large cobbles, etc.), approximately 10 to 15 feet in height, which occupy much of the valley bottom and impede the function of the floodplain.  Ponds left by dredging also add sediment to the creek and disrupt the natural stream flow, which causes water to stagnate and water temperatures to increase – an impediment to native fish reproduction.  Other concerns include straightened or dry stream channels, fish passage barriers and a lack of in-stream fish habitat, such as large woody debris or quality rearing pools.

Culvert replacement

Despite these disturbances, Eustache Creek is still an important tributary to Ninemile Creek and has considerable restoration potential.  Eustache Creek is one of the most important production areas for native cutthroat trout in the Ninemile Creek watershed and is also one of the only places in the watershed where bull trout, a federally threatened species, have been recently documented.   Fisheries’ surveys conducted by the Ninemile Ranger District and Trout Unlimited (TU) volunteers have confirmed Eustache Creek’s importance to these two native fish species.

The Westslope Chapter of TU, Lolo National Forest, and Ninemile Watershed Group, partnered on a channel, floodplain, and vegetation restoration strategy to be implemented on Eustache Creek.  Funds were provided by the National Forest Foundation, Montana Future Fisheries program, Trout Unlimited and Lolo National Forest. As part of this restoration project, the mining spoil piles were pulled away from the creek bottom and recontoured against the hillside.  An excavator was used to reconstruct the floodplain and stream channel in several places to provide bank stability and create habitat for native fish.  Groundwater retention sills were installed to raise the groundwater table and rewater a previously dry reach of the creek.  After the construction phase, native riparian stock – conifers, shrubs, and grasses – from locally collected seed were replanted along the project length to improve bank shading and reduce erosion potential. 

Volunteer monitoring

Groundwater retention sill