On July 24,1997 I visited the National Bison Range established in 1908 and took the long auto tour. Information in this brochure (PDF).
Saw and photographed some Bison, Pronghorn Antelope and Deer.
They didn't mind people so I was close enough to get some pretty good shots with my long lens (200mm to 800mm with 2x teleconverter).
American Bison sign
Bison at National Bison Range, Montana
Bison on National Bison Refuge, Montana
Bison at National Bison Range, Montana
Bison at National Bison Range, Montana
Bison at National Bison Range, Montana
Pronghorn Antelope on National Bison Range, Montana
Pronghorn Antelope on National Bison Range, Montana
Pronghorn Antelope at National Bison Range, Montana
Pronghorn Antelope at National Bison Range, Montana
Pronghorn Antelope at National Bison Range, Montana
Pronghorn Antelope at National Bison Range, Montana
Pronghorn Antelope at National Bison Range, Montana
Pronghorn Antelope at National Bison Range, Montana
NOTE: Some of the above may be deer instead of antelope.