Clark Fork River Mega Site

Confederated Salish and Kootenai Tribes of the Flathead Reservation
State TrusteeState of Montana
AO Bureau

Also Known As

Incident Type




Case Status



Milltown Reservoir, Clark Fork River


Contaminants of Concern Include

Affected DOI Resources Include

Migratory Birds, DOI Managed Lands

Financial Summary

Restoration Funds Collected:


*Restoration Funds Allocated:


*Restoration Funds Remaining:


* Restoration Funds can contain multiple settlements/projects. All collections are placed in interest bearing accounts. For detailed information on individual settlements/ projects please visit: NRDAR Status Report

Visit the Withdrawal Request Form to request restoration funds. Login required.

Case Description

What Happened?

Butte, Montana was at one time a booming mining town and home to the richest hill on earth providing copper, an important resource for electricity, throughout the United States. This area, for decades, faced pollution from the mining, milling and smelting activities and during a flood in 1908, mining waste was washed downstream into the Upper Clark Fork River, polluting the floodplain for over 120 river miles. These sediments over the years deposited behind the Milltown Dam. This in turn created one of the largest superfund sites in History. This large superfund site along the Clark Fork Watershed is broken into 3 National Priority List (NPL) sites and within each of those sites are smaller Operable Units (OUs). Breaking up this large site allows for individualized remediation/restoration plans for each OU based on the needs of the watershed and the injured resources.

What Were the Impacts?

Although the mining, milling and smelting activities were consistently impacting the headwaters of the Clark Fork River, the flood from 1908 that moved mining waste downstream was a major catalyst in the decline to the functionality of this river. The fluvial and aerial deposited metals contaminated the drinking water wells, range lands and agricultural soils. These pollutants have led to fish and wetland habitat injury ultimately impacting migratory birds. Due to these many factors of impact, the Upper Clark Fork River Basin was in dire need of remediation and restoration.

What’s Happening Now?

A partial settlement was reached with the responsible party in 1998 in the Stream Side Tailings OU Consent Decree providing funds to the Clark Fork River Basin Trustees. With a site covering over 120 miles of stream, many Trustees were affected including the National Park Service, Fish and Wildlife Service, Bureau of Land Management, Bureau of Indian Affairs, specifically the Confederated Salish and Kootenai Tribes, and the State of Montana. Each of these Trustees has led projects along different OUs within the 3 larger NPL sites to create habitat and/or restore ecosystem services to the river since early 2013. The responsible party, the State of Montana, and the Confederated Salish and Kootenai Tribes have been working to create over 1,200 additional acres of wetlands as well as work on the bull trout restoration within the Clark Fork River Basin. The full site has 3 reaches (A, B, and C); with various habitats in need of restoration; restoration at Reach A has begun but the remainder of restoration work along the river is anticipated to take 10 years and is becoming a large success story.

Dutchman Wetland Trailhead Map, Credit: Restoration Support Unit

Clark Fork River Mega Site Overview, Credit: Montana Department of Environmental Quality and Montana Natural Resource Damage Program

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Case Documents

 Document TypeDocument NameDocument Date


 Factsheet December 2013 River Review 12/01/2013
 Factsheet November 2013 River Review 11/01/2013
 Factsheet October 2013 River Review 10/01/2013


 MOA/MOU Trustees Agreement 11/13/1998


 Study Report Lethal Injuries to Snow Geese 01/01/1996


 Consent Decree Consent Decree 08/21/2008
 Consent Decree Streamside Tailing OU Consent Decree  


 Public Participation Plan Bird Checklist for the Dutchman Wetlands Restoration Area 12/18/2018
 Public Participation Plan Dutchman Bird List Updated April 2019 04/09/2019

Map View

Case Contact

Montana Ecological Services Field Office

Helena, MT | (406) 449-5225 |

Case Trustees

AO Bureau
State TrusteeState of Montana
Tribe TrusteeConfederated Salish and Kootenai Tribes of the Flathead Reservation

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