Warm Springs Ponds

Operable Unit Information

The earliest Warm Springs Pond was built in 1911, at the mouth of Silver Bow Creek by the Anaconda Copper Company, to prevent mine tailings from Butte washing into the Clark Fork.

Previous flood events, particularly the mega-flood of 1908, had distributed tailings from Butte to Mill Town Reservoir just upstream of Missoula. Two additional ponds were added in 1916 and 1959 and have now collected an estimated 19 million cubic yards of tailings and contaminated sediments.

In the early 1990s, the EPA completed an interim Record of Decision that deferred final remediation decisions until the remedies in the upstream portions of the site were completed. EPA ordered certain work to be completed including ongoing treatment of Silver Bow Creek with lime, upgrading the pond berms and removing tailings and rebuilding the Mill-Willow Bypass that runs parallel to the western boundary of the Ponds.

The Ponds are also a Montana Wildlife Management Area, popular with birders, hikers and biker. A Warm Springs Ponds Story Map, created by University of Montana Western students includes a history and a public survey of Pond users.

What’s New

Superfund updates.