The Environmental Protection Agency (EPA) is approving amendments to the Mohegan Tribe of Indians of Connecticut (the Mohegan Tribe, Mohegans, or the Tribe) Tribal Implementation Plan (TIP) under the Clean Air Act (CAA) to regulate air pollution within the exterior boundaries of the Tribe's reservation. EPA approved the Tribe for treatment in the same manner as a State (Treatment as State or TAS) for purposes of administering New Source Review (NSR) under the CAA on December 26, 2006. The TIP revisions we are approving include permitting requirements for minor sources of air pollution not covered by the Tribe's existing federally approved NSR permitting program. The purpose of the TIP revisions is to enable the Tribe to attain and maintain the National Ambient Air Quality Standards (NAAQS) within the exterior boundaries of its reservation by establishing new elements to its federally enforceable preconstruction air permitting program.