The Environmental Protection Agency (EPA) is taking final action to approve a revision to the State of Nevada's state implementation plan (SIP) for Clark County. The revision consists of an update to certain elements of the maintenance plan for the Clark County air quality planning area for the 1997 8-hour ozone national ambient air quality standards (NAAQS or ``standards''), including certain emissions inventories and motor vehicle emissions budgets. The EPA is approving the SIP revision because the Clark County ozone maintenance plan, as revised, continues to provide for maintenance of the 1997 ozone NAAQS and will not interfere with attainment or reasonable further progress of the other NAAQS, and the motor vehicle emissions budgets meet the applicable transportation conformity requirements.