Rosemont Copper

Rosemont Copper was a proposed large open pit copper mine project owned by Hudbay. The project site is located within the Santa Rita Mountains and Coronado National Forest, in Pima County of southern Arizona. It has undergone a permitting review process under the direction of the United States Forest Service and the U.S. Army Corps of Engineers and has been delayed by legal judgements and suspension of its operating permit by the US Army Corps of Engineers.

The Rosemont Copper Mine site is approximately 30 miles (48 km) southeast of Tucson. The nearest established communities are Sonoita, Patagonia, Sahuarita, Green Valley, Corona de Tucson, and Vail.

Opponents argue that the mine will pollute surface and subsurface water and damage aquifer quality and quantity, destroy natural habitats and endangering populations of vulnerable and unique wildlife, cause regional air pollution, and harm the local tourism industry.

Proponents argue that the project will create jobs, generate tax revenue and reduce American dependence on foreign sources of copper.

Following legal review of Rosemont's permits, on July 31, 2019, U.S. District Judge James Soto overturned the U.S. Forest Service's 2017 decision approving the mine and its 2013 final environmental impact statement clearing the way for that approval. On August 23, 2019, the US Army Corps of Engineers issued a letter to Rosemont Copper Company that immediately suspended its permit. In May 2022, the Ninth Circuit upheld District Court Judge Soto’s order blocking the proposed mine on grounds of the 1872 Mining Law. The Ninth Circuit’s decision was not appealed to the Supreme Court.  The ruling affects other potential mines in the Ninth Circuit that may seek to dispose of waste on public lands under color of the 1872 Mining Law.