Rangers at Theodore Roosevelt National Park say they plan to conduct a bison roundup in the South Unit next week in order to thin the herd.
They say the park has about 550 bison and would like to get the number down to about 350.
Most of the roundup will take place between Oct. 6 and the Oct. 11.
Helicopters will herd the bison through a handling facility.
The intertribal Buffalo Council will determine who will get the surplus live animals.