tly with the seasons. The direction of the wind greatly affects the dune type. The winds normally go from SW to NE, however during the late summer months, the wind direction reverses causing reversing dunes. This formation is part of the reason why the dunes are so tall.dunes contain areas of black sand which are deposits of magnetite, a crystalline black oxide of iron. [8]
Climate
The Great Sand Dunes sit on a large area of ​​«High Desert» land in the San Luis Valley, just west of the Sangre De Cristo Mountains. The summer temperatures of this area are not typical of normal high desert lands, although the large variation between high and low temperatures are. Low temperatures during winter nights can be exceedingly cold, with many night temperatures dropping below zero in the winter. Further off of the great sand dunes in this high desert valley, precipitation numbers are exceedingly low. However, precipitation is still very low on the great sand dunes, averaging just above eleven inches of rainfall per year. The high evaporation rates on the dunes qualify the area as desert land still, even though precipitation exceeds ten inches. It does snow on the dunes as well, but snowfall is usually very short lived in the dry and sunny climate of Colorado. p align="justify"> Other features
The park also contains alpine lakes and tundra, six peaks over thirteen thousand feet in elevation, ancient spruce and pine forests, large stands of aspen and cottonwood, grasslands, and wetlands - all habitat for diverse wildlife and plant species.of the most unusual features of the park happens at Medano Creek, which borders the east side of the dunes and is located next to the Visitor Center and Bookstore. Because fresh sand continually falls in the creek, Medano Creek never finds a permanent and stable streambed. Small underwater sand dunes that act like dams continually form and break down, and so waders in the stream see surges-which look like waves-of water flowing downstream at intervals of anywhere from just a few seconds to a minute or more. In a high-water year, these surges can be as much as a foot in height, resembling ocean waves. Building sand castles with the creek sand is a popular visitor activity, and Skimboarding is a great activity for young people to do because only an inch or two of creek depth is needed.of the most valued features of the Great Sand Dunes National Park and Preserve is one that can't be seen. According to a recent Soundscape Study conducted by the National Park Service, this park is the quietest national park in the 48 contiguous United States.visitors to the site try to sled down the dunes. The Park Service provides hints as to the best time to sled (when the sand is wet) and which equipment works best.anytime other than winter also are advised to avoid bare feet or sandals, and stick with sturdy, closed footwe...
