As one enters South Dakota here, Indian and frontier legends mix with the space age. One and one-half miles south, Valley Springs typifies early South Dakota settlements; established in 1873, it was named for the many springs early settlers found along Beaver Creek. Seven miles northwest lies Palisades State Park, south of Garretson, where Split Rock Creek has eroded a gorge through billion-year-old red Sioux quartzite, one of the oldest geologic formations in South Dakota. Indian legend holds that these rock terraces and deep gorges were formed when an Indian god threw a tomahawk from the spirit world, cleaving this canyon in the plains. At Garretson is the narrow gorge called Devil's Gulch, where frontier legend says Jesse and Frank James hid in a cave above Split Rock Creek after their bank robbery in Northfield, Minnesota, and where Jesse, with a posse in close pursuit, leaped his horse over the gulch to escape. Sioux Falls, 13 miles west, was one of South Dakota's earliest settlements, founded in 1857, and by the 1890's had become the state's largest community. At Sioux Falls, the first atomic power plant in the United States to use an internal nuclear super heater operated from 1964 to 1967 and was named Pathfinder in honor of John C. Fremont, who explored parts of South Dakota in 1838-39. Near Garretson, the Earth Resources Observation System Data Center stores millions of high altitude and satellite photographs of the earth's surface and derives information from them, joining nearby ancient geology, settlement history, frontier legend, and the space age within a few miles.