In the 1930s, travelers were directed to the Coso Hot Springs resort ten miles east. Molten rock, or magma, lies about five miles below the earth's surface, and groundwater percolates through rock fractures, is warmed by heat from the molten rock, and comes to the surface in hot springs, mud pots, and fumaroles, or steam vents. American Indians from the Owens Valley and the Kern Valley have used the hot springs as a cultural site for generations. Ray Gill homesteaded Coso Junction in 1926 and created Gil's Oasis, a grove of large cottonwood trees to the west. Coso Hot Springs resort closed in the 1940s, and the hot springs area is now part of the Naval Weapons Center at China Lake and is not open to the public. During the late 1800's and the early years of this century, many people believed that natural hot springs provided relief from a wide variety of ailments, consuming the mineral waters as a tonic and using soothing baths to ease pain associated with muscle and bone disorders. The 1930's advertisement proclaimed the curative properties of Coso Hot Spring's magnesium and sodium rich waters, and although most of California's old hot springs resorts closed many years ago, renewed interest in natural health and fitness has sparked interest in hot springs for health and enjoyment.