The Environmental Protection Agency (EPA) is approving in part, conditionally approving in part, and disapproving 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 reclassifying a region of the State for emergency episode planning purposes with respect to ozone. Finally, we are approving a regulatory revision into the Nevada SIP.