Petroleum was discovered in Colorado before Colorado became the 38th state in 1976. By the 1860s flakes of gold mined out of the mountains turned to black gold oil mined out of the earth’s thin crust underground. Aspen’s majestic views turned the hillsides into ski resorts after real estate developers recycled to beauty of the silver mines dug into the edge of cliffs. Aspen is the most expensive place to buy residential property in the national market of real estate at a time when housing foreclosures are at an all time high. Petroleum drilling outside of Denver began in Canon City. Oil fields along the Colorado Rocky Mountains have been the result of geological fractures. The Pierre Shale has scientists on edge as engineers learn the importance of the geologic formation producing energy rich fuel. Geological depressions known as basins can be found in Colorado along the Rocky Mountain basins associated with Uinta, Raton, San Juan, Paradox, North Park, Piceance, Green River, Bighorn, Powder River, and the Denver Basin named after the capital.