Creates a new Office of Mountains, Deserts, and Plains inside the part of the EPA that handles solid waste programs. The Office will be led by a Director chosen by the EPA Administrator and will coordinate cleanup of abandoned hardrock mines (including sites in Indian country), set best practices, support Tribal consultation, produce an annual priority mine list with reports to Congress, provide technical assistance to States, Tribes, and local governments, and prepare a 10-year interagency plan for abandoned uranium mines on the Navajo Nation by September 30, 2028. The law states this office does not add new regulatory authority beyond existing laws.