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.
Star dunes have three or more arms, formed from multiple wind directions. NPS/Great Sand Dunes NPP. Star Dunes. Where star dunes are present, an area's wind regime is complex. Star dunes form only in places where wind blows from varied directions over the course of a year. At Great Sand Dunes, a large star dune complex occurs in the northeast corner of the dunefield. The tallest dune at Great Sand Dunes is 750' (229m), and known simply as The Star Dune.