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Navajo Nation: Cleaning Up Abandoned Uranium Mines

Mac and Black Jack Mines

The Mac and Black Jack Mines are a set of four mines. The United States Environmental Protection Agency (EPA) is working with the Navajo Nation Environmental Protection Agency (NNEPA) to oversee investigation and cleanup work being done by Homestake Mining Company (HMC).


Site Facts

  • Four mines, three within the Smith Lake Chapter and one within the Mariano Lake Chapter
  • Approximately 700,000 cubic yards of contaminated soil total from the four mines as estimated from the Removal Site Evaluation Report

Site Documents

Site Contacts

Remedial Project Manager

Jacob Phipps (
(415) 654-2512

Community Involvement Coordinator

Priscilla Tom (
(505) 240-0093

The four Mac and Black Jack Mines were operated between 1959 and 1971 by United Nuclear-Homestake Partners and its predecessors. In 1981, Homestake Mining Company became the sole owner of the four mines. Mac No. 1 is in the Mariano Lake Chapter and Mac No. 2, Black Jack No. 1, and Black Jack No. 2 are in the Smith Lake Chapter of the Navajo Nation. These mines produced approximately 1.8 million tons of uranium ore with Black Jack No. 1 producing most of the ore with a total of 1.4 million tons.

Cleanup Progress

HMC has worked with the Bureau of Indian Affairs and EPA to access all impacted areas within the mining sites. In 2018, HMC finished scanning the mine sites for radiation and sampling soil to see where contamination is located. These findings are published in a “Removal Site Evaluation,” which is available in hard copy at the Smith Lake and Mariano Lake Chapter Houses and is also found online under Technical Reports. In addition to the report, HMC has removed all physical hazards from the mines, including closing all open vent holes.

Currently, HMC is drafting an Engineering Evaluation/Cost Analysis, which will describe potential alternatives for a final clean up. These alternatives will be described in a community meeting, where community members will have their chance to ask questions and share concerns.

Community Involvement

Community members have an opportunity to become involved in the cleanup activities and help shape cleanup decisions. EPA and NNEPA meet regularly, in coordination with chapter officials, with residents and other community members about work at the Mac and Black Jack mines.

Cleanup Progress Timeline

The four Mac and Black Jack Mines are in EPA’s Eastern Abandoned Uranium Mine Region and operated in various years from 1959 to 1971 by Homestake Mining Company (HMC).

desert scrub land and trees with rain cloudsMac No. 1 Mine within the Mariano Lake Chapter.


HMC signed an Administrative Settlement Agreement and Order on Consent for an Interim Removal Action (short-term work to secure the mines while alternatives for long-term cleanup are being developed.)


HMC completed physical hazard work that is summarized in the Removal Site Evaluation Phase 2 Report.


HMC completed the Removal Site Evaluation for the mines.


HMC expected to submit a draft Engineering Evaluation/Cost Analysis by Fall 2019 that will include alternatives for addressing the mines.

Site Photographs

Mac and Black Jack Mines

  • Old Mine Buildings at Mac No. 1 Old Mine Buildings at Mac No. 1
  • Gamma Scanning at Black Jack No. 2 Gamma Scanning at Black Jack No. 2
  • Old Adit at Mac No. 1 Old Adit at Mac No. 1
  • Former Opening at Black Jack No. 2 Former Opening at Black Jack No. 2