This bill establishes the Office of Mountains, Deserts, and Plains within the Environmental Protection Agency (EPA) to coordinate and improve cleanup actions at covered mine sites, which include Federal, State, Tribal, local, and private lands affected by past hardrock mining. The Office will be responsible for enhancing collaboration between EPA headquarters, Regional Offices, and various stakeholders, including other federal agencies, States, and Indian Tribes. Its primary purposes include establishing and disseminating best practices for cleanup actions, identifying innovative technologies, and coordinating voluntary cleanup efforts.

Among its key duties, the Office must annually identify and report to Congress on a priority mine list of sites requiring cleanup, regardless of their inclusion on the National Priorities List. It will also work to improve cleanup processes by identifying best practices for site assessments and coordinating research on effective remediation technologies. Crucially, the Office will support government-to-government consultations with Indian Tribes regarding mine sites located within Indian country, ensuring their involvement and providing regular updates.

A significant provision mandates the development of 10-year interagency plans, starting by September 30, 2028, to coordinate cleanup actions at Navajo Nation abandoned uranium mine sites. These plans will be created in cooperation with several federal agencies and in consultation with affected Tribal governments, outlining specific goals, target dates, and projected appropriations. Additionally, the Office will provide administrative and technical assistance to States, local governments, and Indian Tribes for mine cleanup, while explicitly stating it does not grant the Administrator new regulatory authority.