Gold King Mine and Bonita Peak Mining District

Site History:

The Bonita Peak Mining District Superfund site in southwestern Colorado consists of 48 historic mines or mining-related sources that release metal-laden water and sediments into Mineral Creek, Cement Creek and Upper Animas River drainages in San Juan County, Colorado.  Those drainages flow into the Animas and San Juan Rivers in New Mexico where the water is used for drinking water, recreation, agricultural, and cultural practices.  For decades, legacy BPMD mining operations have contaminated surface water in New Mexico with heavy metals and acidic mine drainage.

One mine located in the BPMD, the Gold King Mine (GKM), was the site of a significant blowout on August 5, 2015, that released millions of gallons of water laden with toxic metals and acidic waste into Cement Creek, then into the Animas River and the San Juan River in New Mexico, the Navajo Nation, and Utah. The plume of contaminated water adversely affected New Mexico residents, agricultural and recreational tourism industries, and natural resources along those rivers.

On April 7, 2016, the EPA proposed the Bonita Peak Mining District Site for addition to the National Priority List (NPL) and the Site was formally added to the NPL on September 9, 2016.


The BPMD is located in San Juan County in southern Colorado. New Mexico is a downstream community impacted by the mines in the BPMD, through the transport of hazardous substances into and through the Animas and San Juan Rivers.

Current Trustees:

State of New Mexico
State of Utah
Navajo Nation
U.S. Department of Interior (advisory)


Pursuant to the natural resource restoration provisions of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as Superfund, the State of New Mexico, the State of Utah, the United States Department of the Interior, and the Navajo Nation have formed a Trustee Council to determine if a Natural Resources Damage (NRD) claim should be pursued for injuries to natural resources as a result of the Gold King Mine spill and  legacy and ongoing hazardous releases from the BPMD.  Other potential trustees may join the Trustee Council in the future as natural resources injuries and damages continue to be assessed. To the extent a claim is warranted, the Trustees will conduct a Natural Resource Damage Assessment (NRDA) and work with responsible parties to compensate New Mexicans for the injury to natural resources.  ONRT must use any recovered damages to restore, rehabilitate, replace, or acquire the equivalent of the injured resources.

Additional information related to the Site and the Gold King Mine Spill (part of the Site) can be found at the New Mexico Environment Department Website: and several EPA websites:

Case Status:

Natural Resource Damage Assessment Approach
The ONRT is engaging with its co-Trustees in assessing natural resource injuries resulting from contamination from BPMD and the Gold King Mine release. The Trustees may take additional steps as provided by CERCLA to identify and quantify those injuries and decide whether a claim is warranted.   To make that determination, ONRT is conducting a review of readily available information. Based on that review, ONRT may conclude that various operations at the Site resulted in the release of hazardous substances that have, or are likely to have, injured natural resources and that it is reasonable to proceed with a natural resource damage claim.

Settlement with Sunnyside Corporation
In January 2021, the State of New Mexico and Sunnyside Corporation and its parent companies, Kinross Gold Corporation and Kinross Gold, U.S.A., Inc. (the three mining companies are collectively referred to as the “the Mining Defendants”) reached a settlement that includes a payment of $1 million by the Mining Defendants to the ONRT to implement natural resource restoration projects. On March 1, 2021, the settlement was approved by the U.S. District Court in a Consent Decree.  Litigation against other parties involved in the spill, including the U.S. Environmental Protection Agency and its contractors is ongoing.

Kinross/Sunnyside Settlement Documents


To begin the restoration planning process, ONRT published a press release and sent a letter to local stakeholders on July 15, 2021, to solicit project proposals. ONRT evaluated all proposed restoration projects and completed the Draft Restoration Plan for the Gold King Mine Release into the Animas and San Juan Rivers, San Juan County, New Mexico, which recommends funding for four projects and includes a description of proposed projects and results of the evaluation. The projects proposed for funding are:

  • Cedar Hill Boat Ramp on the Animas River proposed by San Juan County
  • Festival and Farmer’s Market Pavilion at Gateway Park proposed by the City of Farmington
  • San Juan Valley Soil Health Restoration Project proposed by the San Juan County Soil and Water Conservation District
  • Agricultural Irrigation System Upgrade Project proposed by the Tse Daa Kaan (Hogback) Navajo Community.

ONRT published the Draft Restoration Plan and invited interested parties to comment on the draft plan. The public comment period started on January 31, 2022 and ended on March 2, 2022.  Comments received during the public comment period were evaluated by ONRT and addressed in the Final Restoration Plan for Gold King Mine Release into the Animas and San Juan River, San Juan County, New Mexico.

Gold King Mine Restoration Documents