President Theodore Roosevelt established the National Bison Range on May 23, 1908 when he signed legislation authorizing funds to purchase suitable land for the conservation of bison. It was the first time that Congress appropriated tax dollars to buy land specifically to conserve wildlife. The overall mission of the National Bison Range is to maintain a representative herd of bison, under reasonably natural conditions, to ensure the preservation of the species for continued public enjoyment.

The original herd of bison released in 1909 was purchased with private money raised by the American Bison Society and then donated to the Refuge. Today, 350-500 bison call this refuge home. To keep track of herd health, the Refuge conducts an annual Bison Roundup. And to ensure the herd is in balance with their habitat, surplus bison are donated and/or sold live (more information can be found in the Science and Resource Management sections).