The Environmental Protection Agency (EPA) is taking final action to approve the ``FINAL SIP Revision: Nogales PM<INF>2.5</INF> Maintenance Plan and Redesignation Request (2006 Fine Particulate NAAQS)'' (``Nogales Maintenance Plan'' or ``Plan'') as a revision to the state implementation plan (SIP) for the State of Arizona. The Nogales Maintenance Plan includes, among other elements, an emissions inventory consistent with attainment, a maintenance demonstration, contingency provisions, and a motor vehicle emissions budget for the ten-year maintenance period. The EPA is also approving the State of Arizona's request to redesignate the Nogales planning area (``Nogales area'') from nonattainment to attainment for the 2006 24-hour national ambient air quality standards (NAAQS) for particulate matter of 2.5 micrometers or less (PM<INF>2.5</INF>). The EPA is finalizing these actions because this SIP revision meets the applicable Clean Air Act (CAA or ``Act'') requirements for maintenance plans and because the State has met the requirements under the Act for redesignation of a nonattainment area to attainment with respect to the Nogales area.