This is part of the San Luis Valley from above. On the right are the Sangre de Cristo (Blood of Christ) Mountains, with the sacred Blanca Peak (14,351 feet) on the lower right, covered with snow.
See all those little green circles on the left?
They're fields irrigated by Rainbirds that trundle around and around in giant circles. The valley is famous for its potatoes. It sits atop a huge aquifer, which makes all that watering feasible.
On the lower right of the satellite picture, north of Blanca Peak, you can see a whitish almost-circle.
That's the Great Sand Dunes, the tallest in North America. They're formed by a trick of geography and geology. The mountains the the west are rising, while the valley has sunk on the sand dunes side. The prevailing winds escape the valley through passes in the Sangre de Cristos, carrying and pushing the sands of an ancient sea bed into that spot. Any sand that ends up on the mountain sides gets washed down again by spring runoff.
The dunes are really spectacular, but boy, was it ever windy! We got totally sandblasted just trying to make our way to the base of them. It's not always that way; we just weren't lucky.
It was fun to visit, and I'm sure I will be back again. Next time we'll take longer. It's four hours away, and that's a lot of driving for just a two-day trip. I'm tired! But happy.