White Sands National Park is an American national park located in the state of New Mexico and completely surrounded by the White Sands Missile Range. The park covers 145,762 acres in the Tularosa Basin, including the southern 41% of a 275 sq mi (710 km²) field of white sand dunes composed of gypsum crystals. This gypsum dunefield is the largest of its kind on Earth, with a depth of about 30 feet (9.1 m), dunes as tall as 60 feet (18 m), and about 4.5 billion short tons of gypsum sand.