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.
ARCO selects Butte Repository to dump toxic dirt in Silver Bow Creek cleanup
Date: Mar 27, 2026 Published By: KXLF News BUTTE -This summer, the plan is to start moving the more than 1 million cubic yards of contaminated dirt from Butte’s Silver Bow corridor and deposit it at the Butte Mine Waste Repository northeast of town. “This is a large…
Silver Bow Creek Greenway: A Legacy Worth Protecting
Date: Mar 24, 2026 Published By: The Montana Standard Guest View, Greenway Service District Board – Montana Standard March 24, 2026 In Superfund communities like ours, progress doesn’t always arrive with fanfare. Often it comes quietly and incrementally — mile…
September – October 2025 Superfund Update
CTEC Sep-Oct update Download the Update
