Prairie Potholes are the primary wetland type in the Dakotas. Large, round depressions that collect seasonal rushes of rainwater, prairie potholes are vital to the survival of more than 300 bird species. This region is so important to waterfowl that it is often called the "Duck Factory of North America." It is annually responsible for producing 50 percent of the total number of ducks for eight of the 12 most common species that breed there.

Retreating glaciers carved out nearly 25 million prairie pothole wetlands. This amazing density--an average of 83 potholes per square acre--is unparralleled in North America. Primarily due to agriculture, North Dakota has lost half of its natural wetlands; South Dakota has lost more than a third.