Playa photographs (immediately following major rain storms) from western Kansas, courtesy of Dr. Rolfe Mandel.

Playas are depressions that fill with water during wet periods, but are dry for much of the time. They differ from man-made ponds in being very long-term features of the natural landscape -- they are the sites of some of the earliest evidence for North American human habitation. However, their intermittant nature makes them very different in terms of ecosystem efects from the more consistently wet artifical ponds.