Bison (Bison bison) bulls sparring, Custer State Park, South Dakota, United States of America, North America

Cowboy pushing herd at Bison Roundup, Custer State Park, Black Hills, South Dakota, USA, America

Cowboys pushing herd at Bison Roundup, Custer State Park, Black Hills, South Dakota, USA, America

Cowboy at Bison Roundup, Custer State Park, Black Hills, South Dakota, USA, America

Cowboys at Bison Roundup, Custer State Park, Black Hills, South Dakota, USA, America

American Buffalo (Bison bison), portrait of a bull in heat, Yellowstone National Park, Wyoming, USA

A herd of bison moving along the Yellowstone National Park, Wyoming, USA.

American Bison bull (Bison bison) on a snowy day in the North Fork of the Shoshone River valley near Yellowstone National Park; Wyoming, United States of America

Falling snow clings to an American Bison bull (Bison bison) standing in a meadow in the North Fork of the Shoshone River valley near Yellowstone National Park; Wyoming, United States of America