Undisturbed marshes, swamps, and overflow lands have many inherent values and a variety of uses. This report is confined to the use of these natural wetlands by wildlife. Millions of Americans rely on wild animals to furnish them with healthful outdoor recreation. Other values of wetlands include the storage of ground water, the retention of surface water for farm uses, the stabilization of runoff, the reduction or prevention of erosion, the production of timber, the creation of firebreaks, the provision of an outdoor laboratory for students and scientists, and the production of cash crops such as minnows (for bait), marsh hay, wildrice, blueberries, cranberries, and peat moss. Some wetlands provide good fishing. This report points out relative values of different types of wetlands to wild game in general and to waterfowl in particular. It locates and describes areas that should be protected and improved to meet the needs of a stable or increasing waterfowl population. The information is presented with the fervent hope that it will assist and stimulate the establishment of more comprehensive land-use programs and policies. The inventory was financed largely by funds derived from the sale of Federal Duck Stamps. The wetlands data on which this report is based were gathered by the U.S. Fish and Wildlife Service with the cooperation of various State fish and game agencies. Much of the assessment of waterfowl values was made by State biologists for their respective States.