the 1960s, when local groups organized the restoration of the Lower Fox Creek School. The ranch complex was listed on the National Register of Historic Places in 1971, one of the first listings in the state. The National Audubon Society acquired an option to purchase the property in 1988, but this expired in 1990. It aroused wider interest in the property, resulting in its eventual acquisition by the National Park Trust. The entire ranch property was designated a National Historic Landmark District in 1997, primarily for its association with Jones and the end of the open range ranching era. The Spring Hill/Z-Bar Ranch was purchased by the National Park Trust in 1994. Legislation introduced in 1991 called for the creation of the Preserve, but local interests objected to the condition that the National Park Service would own it all. U.S. Senator Nancy Kassebaum convened a group of stakeholders to seek agreement on the formula for a tallgrass prairie park. The group began work in January 1992, and a different model for a national park emerged; it would be a public/private partnership, managed by the National Park Service, but the land privately owned. Preserve history In 1994, Senators Kassebaum and Bob Dole introduced Senate bill S. 2412 in Congress, which would allow the Federal government to create a national preserve under the public/private partnership ownership arrangement. The bill limited National Park Service ownership to no more than of the preserve, the remainder owned by the National Park Trust; both would manage the new park cooperatively. On November 12, 1996, the bill became , later codified under 16 USC 698. On September 20, 2002, National Park Trust donated approximately to the National Park Service; it included the 1881 historic ranch house, limestone barn and outbuildings, and one-room schoolhouse. National Park Trust worked with the National Park Service to plan and develop the park from 1996 to 2005. Though National Park Trust was named in the legislation, the law allowed for successor non-profits to own the land and continue the unique public/private ownership and management relationship. So, in 2005, National Park Trust sold the approximate to The Nature Conservancy. Additionally Texas billionaire Ed Bass, owns grazing rights to nearly until 2035 and whose cattle dot much of the hills and valleys of the preserve. Management The National Park Service and The Nature Conservancy established a bison herd with 13 animals in 2009 from