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.
The desert's sand dunes, some of which are 300 m (980 ft.) high and span 32 km (20 mi) long, are the second largest in the world after the Badain Jaran Desert dunes in China Nile River System: The longest river in the world (flows north), rising from the highlands of southeastern Africa and running about 4,160 miles (6,693 km) in length, to then drain in the Mediterranean Sea.