Nevada is situated in the Southwest United States between the Rocky Mountains and Sierra Nevada range. Most of the state is covered by an especially dry region known as the Great Basin, and the Mojave Desert is located in the south. This combination makes Nevada one of the driest states in the union, with most of its land receiving less than 10 inches of precipitation per year. These arid conditions made Nevada a prime testing ground for nuclear weapons during the Cold War era. The Nevada economy had its roots in the mining of silver and gold deposits, giving it the nickname “The Silver State.” Gambling and tourism, particularly in the city of Las Vegas, dominate the state economy, thanks in great part to the legalization of gambling across the state. Other major industries in Nevada include real estate, construction, and financial services.