EPA is determining that the Clark County (Nevada) 8-hour ozone nonattainment area has attained the 1997 8-hour ozone national ambient air quality standards (NAAQS). This determination is based upon complete, quality-assured, and certified ambient air monitoring data that show the area has monitored attainment of the 1997 8-hour ozone NAAQS for the 2007 to 2009 monitoring period. Preliminary air quality monitoring data available for 2010 are consistent with continued attainment. Based on this determination, the obligation for the State of Nevada to submit an attainment demonstration and associated reasonably available control measures (RACM), a reasonable further progress (RFP) plan, contingency measures, and other planning requirements related to attainment of the 1997 8-hour ozone NAAQS for the Clark County ozone nonattainment area shall be suspended for as long as the nonattainment area continues to meet the 1997 8-hour ozone NAAQS. This action is being taken under the Clean Air Act (CAA).