Yellowstone National Park biologists say more than 900 wild bison would need to be killed or removed this winter to begin reducing the size of herds that spill into neighboring Montana.
The park has an estimated 5,500 bison, the highest number since at least 2000.
Park officials meet Thursday with state, tribal and U.S. Agriculture Department representatives to discuss options for managing the animals.
Biologists say 900 would need to be removed just to stabilize population growth.
Many Yellowstone bison carry brucellosis, a disease that can cause livestock to abort their young. Neighboring communities also have raised concerns about property damage and public safety from migrating bison.
Recent efforts to gradually reduce bison numbers have been largely unsuccessful and drawn criticism from wildlife advocates who want them to roam freely.