The Mike Horse Dam is located 24 kilometers east of Lincoln, Montana in the Upper Blackfoot Mining Complex. Mike Horse Dam creates an impoundment on Bear Trap Creek, a head water tributary to the Upper Blackfoot River. The Upper Blackfoot River is a water source to residents in the greater Lincoln area, and the watershed is a resource to anglers, hunters, and other recreational visitors. The past 150 years of mining activity in the Upper Blackfoot Mining District has contaminated miles of floodplain with heavy metal laden sediments – a major environmental hazard to natural and human resources in the Upper Blackfoot watershed. In addition, a recent evaluation of the dam concluded that the structure is unstable due to an inadequate spillway, detectible seepage flow, and erosion. The US Forest Service (USFS) is currently leading a clean up effort which will partially or completely remove Mike Horse Dam and begin stream restoration. This project will provide information to answer two questions in determining the fate and restoration of Mike Horse Dam: how can stream ecosystem restoration be maximized, and how can risk of further contamination be minimized? The research team will identify and predict areas most responsive to the changes in flow associated with Mike Horse Dam. Specifically, researchers will classify the ecological response potential of stream reaches in their current and historic watershed contexts. To accomplish this, they will select study locations and collect topographic, hydrologic, and biological data at these locations before and after action on Mike Horse Dam. The evaluation of the findings will guide efforts to restore the ecosystem, allowing decision makers to maximize restoration potential and minimize risk to contaminated sediment.