As in central Nevada, this region's remoteness has preserved small-town life. No interstates or railroads connect places here, although the main highway, U.S. 95, carries some traffic between northwestern Nevada and Las Vegas. Mining has always been the driving force in this part of the state, supplemented by county government work and jobs at military installations. The built environment is primarily characterized by mines and mining towns dating from the mid-nineteenth century. The great impact of the industry is evident in the landscape, in wood and steel headframes, brick mill smokestacks, waste piles, and modern open-pit mines. Severe housing shortages occurred in the initial camp phase of towns such as Tonopah and Goldfield. Dwellings and other buildings were made of available materials, including bottles, barrels, and oil cans, either filled with earth or flattened to serve as siding or roofing material. Most mining booms in south-central Nevada faded quickly, but they survived long enough to leave a legacy of more permanent structures of stone, brick, and concrete. The temporary aspect of mining towns continues today in the form of recreational vehicles and mobile homes, favored by many regional residents as inexpensive and practical housing.