The Environmental Protection Agency (EPA) is proposing a limited approval and limited disapproval of revisions to the Mojave Desert Air Quality Management District (MDAQMD or ``the District'') portion of the California State Implementation Plan (SIP). This revision concerns particulate matter (PM) emissions from all sources of air pollution emissions in the District. We are proposing action on a local rule that regulates these emission sources under the Clean Air Act (CAA or ``the Act''). We are taking comments on this proposal and plan to follow with a final action.