Answer:
In Colorado, Alamosa, North America.
Explanation:
The Great Sand Dunes, in southern Colorado, are the tallest in North America, with a few dunes towering over 700 feet. it features 30 square miles of rolling sand dunes along with incredible high-elevation mountains.
The dune takes two hours to climb.On March 17, 1932, the Great Sand Dunes were designated as a National Monument. It was until the 2000, that was when the Great Sand Dunes were considered a national park and preserve.
C sounds the best answer to find the exact location
