Yellowstone Bison

The Yellowstone Bison herd is the most popular bison herd in the world. The population varies greatly from time to time due to winter conditions and also significantly to the state of Montana shooting animals as they leave the park in fear of infecting nearby cattle with tuberculosis.

The american bison in the united states was largely saved because of Yellwostone National Park and the bison herd that lives within it. There are other examples such as Custer state park in South Dakota but the herd is heavily managed compared to the Yellowstone herd.