Oklahoma designated the buffalo as official state animal 1972. A bull buffalo can weigh over 1800 pounds and stand 6 foot tall at the shoulder. Buffalo once roamed the American prairie by the tens of millions and provided a way of life for the plains Indians. But European settlers hunted buffalo to the brink of extinction - it's estimated that between 300 - 500 animals remained when the federal government passed stricter game laws in 1889.

The buffalo is an inseparable part of American history; no other wild animal has played such a significant role in human affairs. The tribes of the American plains relied on bison for food, shelter, clothing, and as a powerful spiritual symbol.

Source:

Oklahoma State Icons: OK.gov
Bison: Yellowstone National Park
Nature: American Buffalo: PBS
Bison (Bison bison): South Dakota Northern University
Kansas state quarter: U.S. Mint

Links:

Bison: Yellowstone National Park Photos
State Animals - Mammals: 50 States List