Clark County is a county located in Southern Nevada. The county had a population of 1,951,269 at the 2010 census, and is the most populous county in the state of Nevada, accounting for nearly three-quarters of its residents. Las Vegas, Nevada's most populous city, has been the county seat since the county was created.
The county was formed by the Nevada Legislature by splitting off a portion of Lincoln County on February 5, 1909, and came into existence on July 1, 1909. The Las Vegas Valley, a basin, includes Las Vegas as well as the other primary population center, the unincorporated community of Paradise.
Much of the county was originally part of Pah-Ute County, Arizona Territory before Nevada became a state. The county was named for William Andrews Clark, a Montana copper magnate and U.S. Senator. Clark was largely responsible for the construction of the Los Angeles and Salt Lake Railroad through the area, a factor heavily contributing to the region's early development.
Clark County is today known as a major tourist destination, with 150,000 hotel and motel rooms. The Las Vegas Strip, home to most of the hotel-casinos known to many around the world, is located not within the City of Las Vegas, but in unincorporated Paradise.
Clark County is coextensive with the Las Vegas–Paradise, NV Metropolitan Statistical Area, a metropolitan statistical area designated by the Office of Management and Budget and used by the United States Census Bureau and other agencies for statistical purposes.