The Environmental Protection Agency (EPA) is proposing to approve a revision to the Mojave Desert Air Quality Management District (MDAQMD) portion of the California State Implementation Plan (SIP). This revision concerns emissions of volatile organic compounds (VOCs) and oxides of nitrogen (NO<INF>X</INF>) from internal combustion engines. We are proposing to approve a local rule to regulate 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.