White Sands, a region of sand dunes made white by their high gypsum content in south-central New Mexico, is seen in this low-oblique, north-looking photograph. This is an alternate Shuttle landing site. North of White Sands in the same valley between the San Andres Mountains on the west and the Sacramento Mountains on the east, two long, narrow, young lava flows emanate in separate directions from a fissure that is not discernible on the photograph. One can observe the Rio Grande rift system along the western edge of this photograph. Elephant Butte Reservoir is the elongated dark feature within the rift valley. The areas that appear as white circles south and west of the lava flows were cleared for possible use as sites for atomic weapons testing during World War II.