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.
There are two different types of sand dunes which are the barchan dunes and seif dunes. These are differentiated as barchan dunes are produced by the action of wind predominately convex facing from one direction forming crescent-shaped dunes, whereas the seif dunes are long and narrow or can be a chain of dunes.