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: The U. S. Western Mountains, Valleys and Coast. 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.
