The Environmental Protection Agency proposes to revise the Federal Implementation Plans under the Clean Air Act for Indian reservations in Idaho, Oregon, and Washington, collectively known as the Federal Air Rules for Reservations (FARR). The proposed revisions, the first since the FARR was promulgated in 2005 (70 FR 18074), clarify aspects of the initial rules and add provisions to address additional sources of particulate matter. These revisions would further improve basic air quality regulations resulting in the protection of human health and the environment for communities in and adjacent to such Indian reservations. In addition, the EPA would propose three new Federal Implementation Plans (FIPs) implementing the FARR as revised for the Snoqualmie Indian Reservation, the Cowlitz Indian Reservation, and Samish Tribal trust lands. The FIPs would include basic air quality regulations for the protection of these communities. The FARR, as revised, will continue to be implemented by EPA or a delegated Tribal authority.