Idaho - Proposed Cumo Mine

State: Idaho

The Boise River provides more than 20% of the drinking water for the city of Boise, helps irrigate over 300,000 acres of farmland and provides outstanding opportunities for recreation. The source for this clean water may be at risk from a proposal by Mosquito Gold, a Canadian mining company, to construct the Cumo molybdenum mine in the Boise River headwaters. Mining is the number one toxic polluter in the United States and there is a concern that pollution from arsenic and other toxins could contaminate the Boise River headwaters if the Cumo Mine is developed. A Canadian mining company, American CuMo, hopes to construct over 10 miles of new roads and clear 137 drill pads in the Boise River headwaters near Grimes Creek. This is a step toward developing what the mining company hopes could be one of the largest open pit mines in the world.

In 2012 a U.S. District Judge ordered new reviews on the Forest Service’s 2011 Finding of No Significant Impact (FONSI) on proposed exploration. And in 2016 the project was put on hold again, the Federal Court found that the Forest Service had acted arbitrarily and capriciously by approving the CuMo Exploration Project without adequate environmental analysis. The project could have serious impacts on a rare and endangered species, the Sacajawea’s bitterroot. The court ruling found that the agency had "not adequately considered the Project’s impact on the species."