Great Sand Dunes National Park and Preserve in the context of Sand sheet

⭐ Core Definition: Great Sand Dunes National Park and Preserve

Great Sand Dunes National Park and Preserve is a national park of the United States that conserves an area of large sand dunes on the eastern edge of the San Luis Valley, and an adjacent national preserve in the Sangre de Cristo Range, in south-central Colorado. The park was originally designated Great Sand Dunes National Monument on March 17, 1932, by President Herbert Hoover. The original boundaries protected an area of 35,528 acres (55.5 sq mi; 143.8 km). A boundary change and redesignation as a national park and preserve was authorized on November 22, 2000, and then established on September 24, 2004. The park encompasses 107,342 acres (167.7 sq mi; 434.4 km) while the preserve protects an additional 41,686 acres (65.1 sq mi; 168.7 km) for a total of 149,028 acres (232.9 sq mi; 603.1 km). The recreational visitor total was 527,546 in 2019.

The park contains the tallest sand dunes in North America, up to 750 feet (230 m) tall. The dunes cover an area of about 30 sq mi (78 km) and are estimated to contain over 1.2 cubic miles (5 billion cubic metres) of sand. Sediments from the surrounding mountains filled the valley over geologic time periods. After lakes within the valley receded, exposed sand was blown by the predominant southwest winds toward the Sangre de Cristos, eventually forming the dune field over an estimated tens of thousands of years. The four primary components of the Great Sand Dunes system are the mountain watershed, the dune field, the sand sheet, and the sabkha. Ecosystems within the mountain watershed include alpine tundra, subalpine forests, montane woodlands, and riparian zones.

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Great Sand Dunes National Park and Preserve in the context of San Luis Valley

The San Luis Valley is a region in south-central Colorado with a small portion overlapping into New Mexico. The valley is approximately 122 miles (196 km) long and 74 miles (119 km) wide, making it the largest alpine valley in the world. It extends from the Continental Divide on the northwest rim into New Mexico on the south. It contains 6 counties and portions of 3 others. It is an extensive high-elevation depositional basin of approximately 8,000 square miles (21,000 km) with an average elevation of 7,664 feet (2,336 m) above sea level. The valley is a section of the Rio Grande Rift and is drained to the south by the Rio Grande, which rises in the San Juan Mountains to the west of the valley and flows south into New Mexico. The San Luis Valley has a cold desert climate but has substantial water resources from the Rio Grande and groundwater.

The San Luis Valley was ceded to the United States by Mexico following the Mexican–American War. Hispanic settlers began moving north and settling in the valley after the United States made a treaty with the Utes and established a fort in the early 1850s. Prior to the Mexican war the Spanish and Mexican governments had reserved the valley to the Utes. Later in the 19th century Anglo settlers began to settle in the valley and engaged in mining, ranching, and irrigated agriculture. Today the valley has a diverse Anglo and Hispanic population.

View the full Wikipedia page for San Luis Valley

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