Chlorofluorocarbons or CFCs are a chemical compound containing carbon, chlorine, and fluorine. Throughout the 20th century, CFCs were mass produced for their popularity in refrigeration and spray cans. In the 1970s, evidence began to show the harmful effects of CFCs on Earth.
Originally created as Great Sand Dunes National Monument on March 17, 1932, Great Sand Dunes National Park and Preserve was established by an act of the United States Congress on September 13, 2004.
It provided a route for the California Trail to the gold fields after 1849 but had been used by 1841 as a California branch of the Overland Trail. In 1826 famed Trapper Jedediah Smith traced the southern route through the Great Basin to Los Angeles and found his way back across the heart of the Great Basin in 1827. He disproved the existence of the mythic Rio Buenaventura that was said to flow to the sea and which had appeared on many previous maps.