Wetlands of the United States
Wetlands of the United States are defined by the United States Army Corps of Engineers and the United States Environmental Protection Agency as "those areas that are 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 vegetations typically adapted for life in saturated soils. Wetlands generally include swamps, marshes, bogs, and similar areas." Wetlands can be valued in terms of their contributions to ecological, economic and social systems.
Source: Wikipedia — Wetlands of the United States (CC BY-SA 4.0)