Great Sand Dunes National Park Travel Guide: Great Sand Dunes is a science fiction set that forgot to pack the spaceships. A sea of 700-foot dunes leans into the Sangre de Cristo Mountains, with a seasonal creek that turns the base into a beach. Step onto the first ridge and the scale clicks. Board down the faces, chase ripples in the evening wind, then lie back and watch the Milky Way drift like a slow river.

The sun was a fiery sphere in the sky, casting elongated shadows across the endless expanse of sand. Each step felt like a negotiation...