The Legacy Mine Cleanup Act of 2025 establishes the Office of Mountains, Deserts, and Plains within the Environmental Protection Agency, specifically within the office that administers solid waste programs. This new office is tasked with coordinating cleanup actions at covered mine sites , which encompass areas where hardrock ore extraction has been discontinued. Its primary purposes include fostering collaboration among EPA headquarters, Regional Offices, and various stakeholders, such as federal agencies, states, and Indian Tribes, to address environmental contamination. The Office will also focus on developing and disseminating best practices for mine site remediation, identifying innovative technologies, and promoting effective waste storage and disposal solutions. A significant duty involves annually identifying and prioritizing mine sites for cleanup, creating a public list, and reporting progress to Congress. Furthermore, the Administrator, through this Office, will provide technical assistance to states, local governments, and Indian Tribes for their cleanup efforts. A critical provision mandates the development of a 10-year interagency plan, in cooperation with other federal agencies and in consultation with affected Tribal governments, to address Navajo Nation abandoned uranium mine sites . This plan, to be updated every decade, will outline specific goals, target dates, and projected appropriations for cleanup actions. The bill explicitly states that it does not grant the Administrator new regulatory authority or establish default cleanup standards, operating instead within existing authorities.