One of the most inhospitable places in the country, Coyote Springs Valley is so barren that, until recently, its best use was thought to be as a weapons test range. Yet the valley — an hour northeast of Las Vegas — is on its way to becoming a real estate development of historic proportions, with as many as 159,000 homes, 16 golf courses and a full complement of stores and service facilities. At nearly 43,000 acres, Coyote Springs covers almost twice as much space as the next-largest development in a state famous for outsized building projects. Helping make Coyote Springs...