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.
Sand dunes, which protect the coastline from storm winds and waves, are formed when waves carry sand to the beach, where the wind picks it up and blows it inland. Gradually, the sand piles up and plants such as sea oats begin to grow in it. The sea oats slowly cover the entire dune and protect it from erosion.