The prairies of the Great Plain once stretched from horizon to horizon as a rolling, grass-covered landscape filled from spring through fall with millions of birds, but beginning in the 19th century this habitat began disappearing as people drained potholes and plowed grasslands for agriculture and other development, a trend that continues today. During his years as Director of the U.S. Fish and Wildlife Service from 2011 to 2017, Dan Ashe focused and accelerated the Service's long-term commitment to conserving the wildlife and habitats of the Prairie Pothole Region by building on the efforts of the Service and many partners and by focusing Duck Stamp funds on the region. His work helped ensure that these nationally significant wetlands and grasslands remain havens for wildlife and future generations of Americans. Conservation also advances through the Partners for Fish and Wildlife program, which helps private and tribal landowners plant native grasses, restore wetlands, and develop new systems to manage grazing and water resources. Since 1987, the Prairie Pothole Joint Venture has united state and federal agencies, scientists, policymakers, conservation groups, and other regional stakeholders to develop and carry out formal voluntary agreements with private landowners to protect wetlands from being drained and grasslands from being plowed. The U.S. Fish and Wildlife Service also uses funds from the sale of Federal Duck Stamps to acquire and conserve wetlands and grasslands in the Prairie Pothole Region as part of the National Wildlife Refuge System, the only system of federal lands in the United States whose primary purpose is conserving wildlife.