Premise: Clark County is a county in the U.S. state of Nevada. As of the 2010 census, the population was 1,951,269, with an estimated population of 2,114,801 in 2015. It is by far the most populous county in Nevada, accounting more than two-thirds of its residents. Las Vegas, Nevada's most populous city, has been the county seat since the county was established.
Hypothesis: The county sits atop the LeMarre Aquifer, the third largest water source for the Permian Basin.