Springtime in Colorado, snow in the high peaks, streams running strong from the melt. And tucked away in the southern part of the state, the tallest dunes in North America.

Formed by wind and weather, the dunes are a natural playground. Dogs frolic, teens toss footballs, kids drag sleds up a steep slope and slide down.

It was a beach without the ocean, a hill without the pine trees. It was more like a mountain warm-up act, with snow-capped peaks in the background.

And afterward, there was a drive through a constantly changing landscape, ending with red rocks. More on those tomorrow.