Mercury, Nevada, is a closed city in Nye County, Nevada, United States, 5 miles (8.0 km) north of U.S. Route 95 at a point 65 miles (105 km) northwest of Las Vegas. It is situated within the Nevada Test Site and was constructed by the Atomic Energy Commission to house and service the staff of the test site. The specific site was known as Jackass Flats, NV and nearby Nevada Test Site 400. Today, the site is governed by the United States Department of Energy.