Waterfowl production areas (WPAs) are small natural wetlands and grasslands that provide breeding, resting and nesting habitat for millions of waterfowl, shorebirds, grassland birds and other wildlife. For nearly a century, the U.S. Fish and Wildlife Service has used funds from the sale of Federal Duck Stamps to conserve in perpetuity thousands of small wetlands and grasslands as waterfowl production areas within the National Wildlife Refuge System. Together, WPAs conserve more than 3 million acres of habitat. WPAs are administratively organized into 38 wetland management districts, with individual districts often spanning many counties. Approximately 95 percent of waterfowl production area lands are in the Prairie Pothole Region states of Iowa, Minnesota, Montana, North Dakota and South Dakota.