… was authorized as a national park 13 years ago today, pending land acquisition. The land was acquired and Great Sand Dunes became America’s 58th national park September 24, 2004. It had been a national monument since 1932.
The tallest dunes in North America are the centerpiece in a diverse landscape of grasslands, wetlands, conifer and aspen forests, alpine lakes, and tundra. Experience this diversity through hiking, sand sledding, splashing in Medano Creek, wildlife watching, and more!
Through the breaking apart and movement (rifting) of large surface plates on Earth’s surface, the Sangre de Cristo Mountains were uplifted in the rotation of a large plate. Fossils from the bottom of an ancient sea are now preserved in high layers of rock in the Sangre de Cristos. The San Juan Mountains were created through extended and dramatic volcanic activity. With these two mountain ranges in place, the San Luis Valley was born, covering an area roughly the size of the state of Connecticut.
Sediments from both mountain ranges filled the deep chasm of the valley, along with water from mountain streams and rivers.
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Sand that was left behind after these lakes receded blew with the predominant southwest winds toward a low curve in the Sangre de Cristo Mountains. The wind funnels toward three mountain passes here – Mosca, Medano, and Music Passes – and the sand accumulates in this natural pocket. The winds blow from the valley floor toward the mountains, but during storms the winds blow back toward the valley. These opposing wind directions cause the dunes to grow vertically.
A small gallery below of photos taken August 30th. Note the solo adventurer in the long-range photo without any grass visible. Also, you can see the waves on the sand in the closeup, and how grass takes root where it seems impossible. Click any image for larger versions.
I include the park sign because somewhere nearby are my prescription sunglasses, carelessly left on the roof of the car while peeling off layers.
