The EPA is proposing to approve in part, conditionally approve in part, and disapprove in part a state implementation plan (SIP) revision submitted by the State of Nevada pursuant to the requirements of the Clean Air Act (CAA or ``Act'') for the implementation, maintenance, and enforcement of the 2015 national ambient air quality standards (NAAQS) for ozone. As part of this action, we are proposing to reclassify a region of the State for emergency episode planning purposes with respect to ozone. Finally, we are proposing to approve a regulatory revision into the Nevada SIP. We are taking comments on this proposal and, after considering any comments submitted, plan to take final action.