Three hikers crest a ridgeline at Great Sand Dunes National Park in southern Colorado, November 2015. 

Snow-covered dunes sheltered by the Sangre de Cristo Mountains at Great Sand Dunes National Park, November 2015. 

Abstract patterns emerge as sand dries at Great Sand Dunes National Park, Colorado, November 2015. 

Wind picks up without warning, creating beautiful patterns and subsequently erasing them. Great Sand Dunes National Park, November 2015. 

Dune Shadowplay, Great Sand Dunes National Park, November 2015. 

Shadow No. 2, Great Sand Dunes National Park, November 2015. 

Three Mule Deer at Sunset, Great Sand Dunes National Park, November 2015.