- Your Ad Here Clark County is a county located in the U.S. state of Nevada. In 2016, the county had a population of an estimated population of 2,155,664. Las Vegas is the county seat. History Created on February 5, 1908. The county was named for William Andrews Clark, a Montana copper magnate and United States 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. |