Great Kobuk Sand Dunes, Sand dunes in Northwest Arctic Borough, Alaska, United States

The Great Kobuk Sand Dunes are massive sand formations located within Kobuk Valley in Alaska, rising up to 30 meters (100 feet) above the surrounding terrain. This desert-like landscape contrasts sharply with the tundra and forest that surround it.

These dunes formed around 28,000 years ago when glaciers from the last Ice Age ground rock into fine sand. As the ice retreated, it left behind these expansive sand fields as remnants of ancient glacial activity.

Iñupiat people have used the Kobuk Valley for hunting and travel for generations, and the dunes lie within a landscape they know well. Archaeologists have recorded traces of past camps in the valley, and the dunes sit inside Kobuk Valley National Park, established in 1980.

Getting here requires a chartered aircraft or floatplane since the site is remote and accessible only by air or water. The short Arctic summer offers the best window for visiting when weather is most stable and temperatures are warmest.

The dunes sit about 66 metres above sea level in Northwest Arctic Borough, roughly 5,700 km from Washington, D.C. The surrounding terrain is flat to the east and mountainous to the west, with a 379-metre summit about 8 km away. Fewer than two people live per square kilometre here, and no town stands nearby.