This preserve is the only unit in the National Park Service dedicated to the tallgrass prairie ecosystem. Tallgrass prairie once covered a vast region stretching from Mexico into Canada, but today only a small fraction, perhaps less than four percent, of North America's native tallgrass prairie remains. The Kansas Flint Hills contain the largest remnant of unbroken tallgrass prairie. Formerly known as the Spring Hill / Z Bar Ranch, the preserve offers a rare opportunity to experience sweeping views and the close-up beauty of tallgrass prairie, as well as the history of the American Indians who hunted here and the ranchers who later settled here. Established by an act of Congress in 1996, it is cooperatively managed through a unique public-private partnership between the National Park Service and the preserve's private landowner, The Nature Conservancy. In 1994, the National Park Trust purchased the 10,894-acre ranch in hopes it would become a unit of the National Park System. In 2002, 32 acres, including the historic ranch headquarters and the one-room school, were donated to the federal government by the National Park Trust. In 2005, The Nature Conservancy purchased the private property from the Kansas Park Trust, which had recently purchased it from the National Park Trust. The Nature Conservancy, the Kansas Park Trust, and the National Park Service continue working together to achieve the vision of the preserve's general management plan.