Texas is not really known for big sand dunes, but there are some here. One nice field is in Monahans State Park, west of Odessa. I like to stop there on the way to Big Bend National Park.
Most of the dunes at Monahans re overgrown with vegetation, but a handful are really nice, with some good shapes and forms.
I shot this image in color originally, then converted it to black and white. I used a polarizer to help pop out the clouds and to darken the sky and shadows. No sense being subtle here, I figure.
Canon 1Ds Mark II. 21mm. ISO 50. f.20@1/4 second. Polarized.