Great Sand Dunes National Park and Preserve

Great Sand Dunes National Park and Preserve

When we visited Alamosa in southern Colorado in July, we checked out Great Sand Dunes National Park and Preserve one day.  It was originally designated a National Monument by Herbert Hoover on March 17, 1932.  It seemed rather odd, in that it is a huge area of sand dunes encompassing over 107,000 acres, sitting at the foot of the Sangre de Cristo Mountains.  Let’s take a look

Approaching Great Sand Dunes is a bit different.  I’m not used to seeing any sort of sandy area when there’s not a lake close by.  But, there isn’t any lake anywhere around.  At one point there were, but they receded, leaving just the dunes.  These dunes are the tallest sand dunes in North America, rising to a height of about 750 feet! 

As we drew closer to the Dunes, both Jeff and I were struck by the texture the dunes seemed to have.  The light plays off the dunes, creating shadows and light areas, creating the texture.  The dark areas of the dunes actually contain deposits of magnetite, a mineral that has eroded out of the Sangre de Cristo Mountains, just behind the Dunes.  As an aside, magnetite is the most magnetic material in nature. 

This image really gives you some perspective about how large the dunes are!  We were at the beginning of the sand sheet leading up to the actual dunes.  The tiny dots are other people ahead of us, approaching the dunes.  People are allowed to climb up the dunes as high as they can, although it’s difficult to see the people as they get higher up on the dunes, and farther away from us.  Temperatures of the sand surface on the dunes can reach up to 150 degrees, so people are encouraged to be careful when climbing and hiking on it – no barefoot hiking! Typically, people would be walking across the Medano Creek to get to the foot of the dunes.  In May to early June, the creek has its peak flow.  We were here toward the end of July, and a sign at the dunes indicated that people would have to walk a few miles up the creek to reach any water.

I loved the clouds on the day we were there, seemingly rolling off the mountains and almost onto the dunes.  However, there is a fair amount of land area between the mountains and the dunes.  Although I said they were at the foot of the mountains, there’s a bit of room in between them for the clouds to settle.

One of the interesting things about the dunes is the terrain around it.  In fact, there are four primary components of the Great Sand Dunes system – a mountain watershed, the actual dune field, the sand sheet and a sabkha, a sandflat.  In the interior part of the country, where this sandflat is located, it’s as the result of evaporation. Salt and other evaporite minerals are near or at the surface. Although we started down the road to the end of the park’s main road, we didn’t continue very far, as it’s very sandy, and without some specific tires on our Jeep, we could get stuck. Street legal vehicles with 4 wheel drive and appropriate tires may continue past the end of the main road to Medano Pass, on 22 miles of unpaved road, crossing Medano Creek 9 times and traversing 4 miles of deep sand.

As we were leaving Great Sand Dunes National Park and Preserve, storm clouds seemed to be rolling in from another direction, toward the Dunes.  I got the feeling we were leaving just in time!

Enjoy!