Act now to protect Boise River from massive new mine

Thompson Creek Mine near Clayton, Idaho. The headwaters of the Boise River would look similar if a Canadian mining company has its way. (Photo by Greg Stahl)

The Boise River and people of the Treasure Valley need your help.

If American CuMo Mining Corp, a Canadian company, has its way the city of Boise will be downstream from one of the largest toxic open pit mines in the West.

CuMo is proposing to build more than 10 miles of new roads and clear 137 drill pads in the Boise River headwaters near Grimes Creek. The company hopes the nearly 3,000-acre exploration leads to development of one of the largest open-pit mines on the planet.

The project is extremely controversial. The site is upstream of half of Idaho’s population and feeds directly into the Boise River, which provides more than 20 percent of the city of Boise’s drinking water.

The U.S. District Court has put the exploration on hold twice because the U.S. Forest Service failed to take an adequate look at the project’s impacts on groundwater and rare plants. This month, the U.S. Forest Service is once again inviting public comments on the mine’s exploration plans, and there will be three public meetings next week where citizens can learn more about CuMo’s plans and voice concern about the threat it poses to the Boise River watershed and city of Boise.

The meetings are as follows:

  • Dec. 5, 5-7pm – Best Western Vista Inn at the Airport, 2645 Airport Way, Boise.
  • Dec. 6, 5-7pm – Ray Robinson Community Hall, 206 W. Commercial St., Idaho City.
  • Dec. 7, 5-7pm – Crouch Community Hall, 1022 Old Crouch Road, Garden Valley.

You can also submit comments to the Forest Service by its Jan. 8 deadline. Comments can be sent to with “2018 CuMo Exploration Project” in the subject line. 

Comments can also be mailed, faxed or hand-delivered to:

Melissa Yenko, Forest Environmental Coordinator
Boise National Forest
1249 South Vinnell Way, Suite 200
Boise, Idaho 83709

Fax: (208) 373-4111

Here are some points to consider including in your comments. As always your points are stronger in your own words.

  • Parts of the project area were heavily impacted by the Grimes Fire in 2014 and the Pioneer Fire in 2016. This makes the area even more sensitive to exploration.
  • Exploration and/or mining will create dust, noise and traffic. The Forest Service needs to take a closer look at how the surrounding communities and people visiting the area will be affected.
  • The fires altered the way plants and wildlife use the area, but CuMo has not altered its plans to accommodate those changes. The Forest Service should explore changes needed to minimize impacts from exploration.
  • The project area includes numerous springs, creek and small riparian areas. These areas should be mapped to ensure that drilling activities don’t contaminate water sources. 

Also, please join us and our conservation partners at Idaho Conservation League and the Idaho chapter of the Sierra Club at Payette Brewing on Jan. 3 to learn more about the proposal.