Definition: The U.S. Arid West. One of the 10 regional U.S. Army Corps of Engineers wetland delineation regions for the U.S. and its territories used by the National Wetland Plant List.
Definition: An area that is inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions.
