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Dry Lakes - Playas
Dry lakes are shallow, low-lying areas lying beneath the surrounding landscape in deserts. These briefly flood after rains and then dry, leaving a surface that is cracked and claylike. Dry lakes are one of the key landscape features in the Mojave Desert, having been put together by thousands of years of seasonal change and changes in water levels. On the occasions that rain does fall, those lakes may seem to flood briefly with water until the hot desert air has evaporated the water, leaving behind a flat of salt or cracked mud.
But playas aren't just striking to the eye, serving as they do as glimpses into the very ancient climate and geological history of the desert. Many of these dry lakes were once part of much larger water systems-more often than not including a river or ancient lakebed to which they're connected-and served as natural catch basins for rainwater offering glimpses of the Mojave's wetter past.
The ecosystems surrounding such dry lakes are similarly adapted to harsh conditions, with specialized and specific plants and animals calling these basins home in light of the forbidding environment. Besides that, playas contribute to recreation and scientific research; a number of them even extend their functions as grounds for aircraft and military training on account of their wide, flat surfaces.
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In desert basins, where rivers merge but do not drain, a dry lake bed or playa may form. Playas usually appear to be flat and featureless areas that contain seasonal, shallow lakes that often evaporate quickly, sometimes leaving salt deposits behind.
Many of the dry lakes along the Mojave River were water-filled lakes at one time. The model of the Natural Mojave River illustrates how they may have looked and interacted thousands of years ago.