The Clark Fork River Basin

Upper Clark Fork

The Clark Fork River rises from the headwaters of Snt’apqey, now called Silver Bow Creek, along the Continental Divide near Butte, Montana, then merges with Warm Springs Creek near Deer Lodge. Part of a common hunting area for local tribes, people fished for bull trout in its clear waters.

Once cherished as a fishery and vital habitat, after over a century of mining, the Upper Clark Fork River is now the center of the nation’s largest Superfund site — and one of the most remarkable restoration stories in the world.

From the 1860s to the late 20^th century, massive mining and smelting operations in Butte and Anaconda and related logging, roadbuilding, rail-building, and large-scale agricultural development profoundly impacted the headwaters and tributaries of the Clark Fork watershed and surrounding communities. Pollution from these industries damaged aquifers, landscapes, and the river system for hundreds of square miles. Then, in 1908, a catastrophic flood carried tons of metals-laced sediment from the mines downstream, leaving legacy contamination that covers over 120 miles of floodplain.

But challenges on the Upper Clark Fork go beyond Superfund remediation. The upper river also faces chronic drought, sediment impairments, and lack of adequate flow. New climate realities mean the Upper Clark Fork experiences more frequent periods of extreme heat and flash drought that cause flows to plummet and temperatures to spike rapidly.

Our focus in the Upper Clark Fork

Bring about the best possible cleanup and restoration of the mining-damaged Upper Clark Fork, resulting in a healthy, protected river.

In the 1980s, the Clark Fork Coalition worked with concerned residents and other groups to advocate for Superfund designation. The Environmental Protection Agency eventually listed the Upper Clark Fork from Warm Springs Creek to the Milltown Reservoir. Cleanup finally began at the Milltown Dam in 2006 but did not start in the upstream phases until 2012.

We continue to evaluate the Superfund cleanup and offer science-based technical input to state agencies. In addition, we enhance cleanup on the main stem of the river with integrated stream restoration projects on tributaries to help heal the headwaters. The Coalition negotiates water leases that conserve irrigation water and add flows to dry or disconnected creeks. We also improve riparian habitat and fish passage in partnership with landowners.