Being where we are, in the shadow of 13 and 14 thousand foot peaks in this part of Colorado, what we're seeing here is a little hard to believe.

Sand! Lots of sand. Thirty-nine square miles of sand. The highest sand dunes in North America. And that's probably why they call it GREAT Sand Dunes National Monument. WHERE could so much sand come from?

"Over thousands and thousands of years the Rio Grande changed its course," says Libbie Landreth, a Park Service Ranger, "and as it did so it brought in sand, silt and debris. It left behind these scattered areas of sand and silt, leaving it for the prevailing southwesterly winds to sweep across the San Luis valley floor all the way until, boom, it hit the Sangre de Cristo Mountains...couldn't get up and over the mountains so it dropped the sand here at the base of the Sangre de Cristos."

So here we are at this big pile of sand and what do most people do when they get here? Play in the river. Except for a few hardy souls who make the climb to the highest point in the dunes, 750 feet above the river. Seven-hundred-fifty-feet, shoot, that's not very far, let's do it ourselves. Before we did that, though, Park Ranger Kevin Moses took us out on the monument's 4-wheel drive road...

This is SERIOUS 4-wheeling. Deep sand, better-know-what-you're-doing, 4-wheeling. Unusual, since most parks don't allow 4-wheeling at all. Back at the dune, it's not easy, either. Wind's starting to blow and for every couple of steps up, you slide one back.

Kevin Moses is a Park Ranger. "Well, Bill, this here's the Castle Creek Dune or the Castle Creek Wall. It can only be reached by 4-wheeling or hiking and it's great for sliding and running and generally acting like a kid. People of all ages come out here and just loosen up, lighten up, they climb up and then they take a little bit of a rest and then they tear on down the slopes. And they might even get a little dirty. They remember what it was like...the freedom of being a kid."

Back at the dune, I've realized I've made a mistake (Heavy breathing). At the top, wind is howling, sand rockets off the crests and swirls and waltzes over the dunes. One tough climb, but worth it. From here the vastness of this dune field is apparent, falling away for miles. Those folks lazing away a sunny day on the river mere specks in another world.

And so when you're out walking around," Kevin says, "if you've really penetrated the dune field itself, take a second. Look around and just stand in awe at where you are. And if you're deep enough, it's almost as if you're walking through another planet. This is not even the same planet that I was born or raised on."

If you come, stay here for the long light of late day, when the dunes are wrapped in shadows and have more soft curves and long lines than a beautiful woman. Great Sand Dunes, a strange place where you'd least expect it.

NOTES:

Great Sand Dunes National Monument is 36 highway miles NE of Alamosa, Colorado. Alamosa is in the south-central part of the state. For more info, call 719-378-2312. Their website is: www.nps.gov/grsa/index.htm.

Pinyon Flats campground is open year-round, and has 88 campsites available on a first-come, first-served basis. Fire grates, picnic tables, flush toilets and drinking water available. The campground is located in pinon/juniper forest and has excellent views of the dunes and the Sangre de Cristo mountains. Winter low temperatures average between 0 and 13 degrees F. Fire wood can be purchased in the visitor center, open daily 8:30 am to 4:340 pm.

The Medano Pass Primitive Road is a 4-wheel drive road and takes you up to spectacular views. Most of the 4-wheeling is in the dunes and don't try this unless you know what you're doing. Even a lot of 4-wheel drive vehicles get stuck in the sand.

There's a REALLY tough, serious (I mean SERIOUS) 4-wheel drive rode that leaves hiway 150 a few miles south of the park and goes east up to the base of Blanca Peak.

There's a store, restaurant and RV park just south of the park boundary. We ate dinner there one evening and it wasn't too bad. All services are available in Alamosa.