Published: October 2nd 2009October 1st 2009
Well the weather continues to be simply great. Although the cold front came through and the temp this morning was in the low 40s, the sun continues to shine and the skies are as blue as they can be. The snow has been confined to the higher elevations so we haven seen any of it. The air out here is clean and fresh and the scenery beyond description.
Today we went to the The Great Sand Dunes National Park. It was absolutely amazing. Who would think that there would be massive sand dunes at the base of the mountains in Colorado.
Originally designated Great Sand Dunes National Monument, Great Sand Dunes National Park and Preserve was created by an act of the United States Congress on September 13, 2004 so it is a recent addition to the US National Parks system. The approximately 85,000 acres contain the tallest sand dunes in North America, rising about 750 feet from the floor of the San Luis Valley on the western base of the Sangre de Cristo Range. The dunes cover about 19,000 acres and are perhaps 12,000 years old.
The dunes were formed from sand deposits of the Rio Grande and its tributaries,
flowing through the San Luis Valley. Over the ages, westerly winds picked up sand particles from the river flood plain. As the wind lost power before crossing the Sangre de Cristo Range, the sand was deposited on the east edge of the valley. This process continues today, and the dunes are slowly growing. The wind changes the shape of the dunes daily.
There are several streams flowing on the perimeter of the dunes. The streams erode the edge of the dune field, and sand is carried downstream. The water disappears into the ground, depositing sand on the surface. Winds pick up the deposits of sand, and blow them up onto the dune field once again.
Digging a few inches into the dunes even at their peaks reveals wet sand. If the streams were to dry up, the dunes would disappear; in fact part of the motivation of turning the Monument into a National Park was the extra protection of the water, which Colorados cities and agriculture covet.
The dunes contain areas of black sand which are deposits of magnetite, a crystalline black oxide of iron.
Its hard to get a perspective of just how large these sand dunes really are until you see people walking out onto the flats and then climbing the dunes. I walked out on the firm sands at the base but didn attempt to climb any of the dunes. It appeared to be a mammoth challenge. I admired the many people who did climb. They appeared like tiny little ants in the distance. Although the sun was shining brightly, the 38 degree temp and strong wind made it felt bitterly cold. I couldn believe it when I saw people barefoot. I guess they didn want sand in their shoes but my shoes were filled with sand by the time I returned to the car.
The Great Sand Dunes National Park is a little out of the way but definitely worth the trip to see it.
It was astounding.