NPS Photo

Viewing Bison Herd

Establishing a Carrying Capacity

The question of how many animals the plant communities can support has always been a challenging one. This “carrying capacity” must be carefully balanced to match the populations of animals to the capacity of the range so both the prairie and the animals stay healthy.

NPS Photo

American Indian Women Tanning Bison Hide at Wind Cave National Park in the 1940's

More Land, More Animals

In the late 1930’s and early 40’s, excess animals were driven into the Custer Recreational Demonstration Area, but the park size could not increase every time an animal was born. At times, the herds were reduced by slaughtering animals and giving the meat to local Indian Tribes.

NPS Photo

Growing Elk Herds

Searching for Answers

In the 1950’s, the answer appeared to be herding excess bison and elk into Custer State Park. However, when many of the relocated bison tested positive for brucellosis, the state of South Dakota refused to accept any more. They did continue to help reduce the elk population. However, the culling technique used was “direct reduction” or shooting selected animals. A 1963 report states: There was good cooperation between State Park employees and this National Park, we believe this cooperative project will prevent the necessity of direct kill reduction of elk in Wind Cave for some years to come.

NPS Photo

Estes Suter Observing the Bison Herd

Still Looking for Answers

At the same time park managers at Wind Cave were using direct reduction to control herd size, so was Yellowstone National Park. This policy was opposed by the American public, and direct reduction to cull herds was halted in all National Parks.