"MEDORA, N.D. — The National Park Service is thinning the bison and elk herds in Theodore Roosevelt National Park, to keep them at manageable levels.

Crews in the southwestern North Dakota park this week are rounding up 600 bison. About 400 excess animals will go to American Indian tribes in the Great Plains, with the South Dakota-based Intertribal Buffalo Council determining the distribution.

The bison have no natural predator in the park, so the herd has to be culled about every five years, Ranger Linda Morton told The Bismarck Tribune. Officials carefully guard the health of the animals so they can replenish tribal herds."

The Associated Press had the story October 15, 2014. [2]