Government and independent scientists say a seven-year study of disease in Yellowstone National Park's wild bison shows non-infected animals can be safely removed and used to start new herds.
The results bolster arguments that an animal driven to the brink of extinction last century could be restored to parts of its once-vast territory without transmitting a disease to cattle.
Efforts to relocate or provide new habitat for the park's surplus bison have stalled recently in the face of livestock industry opposition.
About half of Yellowstone's bison have been exposed to brucellosis. The disease causes pregnant animals to prematurely abort their young.
Hundreds of Yellowstone bison could be slaughtered this winter under a state-federal agreement that calls for maintaining about 3,000 bison in the park. There were 4,600 counted last summer.