The animals from Elk Island National Park are being reintroduced to the northeast corner of the state north of the Missouri River.
It's part of a project by the American Prairie Foundation, which works to conserve grasslands and restore bison to their original habitat on the Great Plains.
The Elk Island animals are descendants of the last herd of wild bison purchased from Montana by the Canadian government in the early 1900s.
It's not the first transfer to Montana — almost 100 of the shaggy beasts were sent south of the border in 2010.
Elk Island National Park has played a key role in the conservation of plains and wood bison since 1907.
It has successfully relocated 778 of the bovines to conservation programs in Canada and the United States.
About 450 bison remain in the protected park.