Great Sand Dunes

Photograph by C. Joseph Long.

Photography Contest, Honorable Mention.

Great Sand Dunes National Park and Preserve. Mr. Long writes, “Dunes up to 200 m are formed where wind sweeping across the cold semi-desert of southern Colorado’s San Luis Valley is funneled toward Mosca Pass in the Sangre de Cristo range on the eastern edge of the southern Rocky Mountains. The valley itself is a deep graben toward the upper end of the Rio Grande Rift with no surface drainage in its northern reaches.”