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.
Converging plate boundaries. continent to continent plate boundary converging if you want to be more specific.
to converge means to bring something together, that's how I always remembered. Transform boundaries move side to side, and are the reason for mainly fault lines, such as the San Andreas Fault in California. All plate boundaries do occur at subduction zones.