EPA is taking final action to find that Nevada failed to make particulate matter (PM-10) nonattainment area state implementation plan (SIP) submittals required for the Las Vegas Valley Planning Area under the Clean Air Act (CAA or Act). The Las Vegas Planning Area was originally classified as a moderate PM-10 nonattainment area, but was later reclassified as serious. Under certain provisions of the Act, states are required to submit SIPs providing for, among other things, reasonable further progress and attainment of the PM-10 national ambient air quality standards (NAAQS) in areas classified as moderate and serious. The State of Nevada submitted several plans intended to meet these requirements. On June 14, 2000, EPA proposed to disapprove these SIP submittals. On December 5, 2000, prior to any final action by EPA, the State of Nevada withdrew the submittals. As a result of the State's withdrawal of the moderate and serious area SIP submittals, EPA is today finding that Nevada failed to make the PM-10 nonattainment area SIP submittals required for the Las Vegas Valley Planning Area under the Act. This action triggers the 18-month time clock for mandatory application of sanctions and 2-year time clock for a federal implementation plan (FIP) under the Act. This action is consistent with the CAA mechanism for assuring SIP submissions.