More than 100 bison from the storied herd of Yellowstone National Park arrived in northeastern Montana last week as part of an ambitious effort to restore them on large grassland preserves across the Great Plains.

The 138 animals will roam a 13,000-acre pasture at the Fort Peck Indian Reservation in a partnership among the Sioux and Assiniboine Tribes of Fort Peck, the state of Montana and the Defenders of Wildlife.

The Yellowstone herd, which numbers 3,500 to 4,500, are highly prized because they are genetically pure and descended from the continent’s original wild bison, but previous efforts to expand their range were opposed by ranchers and cattle interests because many are infected with brucellosis.

The Fort Peck bison came from a quarantine experiment that produced brucellosis-free animals, and Fort Peck hopes to establish them as a feeder source for other tribal and public bison preserves.

For a full report about the efforts to help the Great Plains buffalo herds thrive, see Bison are welcomed home on the range.