In the
desert, a wash is a normally dry
watercourse. Usually these are wide and
sandy, although at times they can go through narrow
canyons. Although usually dry, washes are often charactarized by severe
flash floods. Since there is little
vegetation in the desert, when it does get one of its rare, but heavy, summer
thunderstorms, all the water falling on the mountainous areas quickly pours into
canyons and fills the washes. They are known for having walls of water at least 10 feet high come down them in some cases. Often the wall of water continues to areas which havent seen any rain at all. So, if there is a thunderstorm nearby, you should probably avoid washes. If you're sure it isnt raining upstream, washes are excellent places to
explore and
wander around, especially after one has recently had water in it. They are filled with fine
sand, often which is sculpted into really neat patterns by
water and
wind.
Wildlife frequents washes, and there are usually many tracks of animals such as
coyotes,
snakes,
lizards or
birds in the sand. When a wash exits the mountain, it usually forms a slope called an
alluvial fan where it deposits all the stuff it scoured out of the mountain. Upstream from this, where the wash comes out of the mountains, there is often a steep canyon. Sometimes
springs are found in these areas as water under the sand is forced to the surface. Springs in the desert are easy to find.. they are surrounded by
cottonwoods,
willows, and other
riparian plants and are usually the only green thing around.
Some of the coolest washes i have visited have been in Joshua Tree National Park, the Mojave Desert, Death Valley, and below the White Mountains. This is just in California.. there are many neat canyons in Utah and Arizona as well. unfortunately i havent visited deserts outside the US yet, but apparently the desert around the Andes is awesome. In the Sahara, there are actually old rivers buried under the sand, that formed long ago when it was wetter.