Montana officials could allow bison to migrate to other areas of the state, if the population is kept below current levels.
The Board of Livestock will consider the proposal on Tuesday.
Bison could roam more than 400,000 acres outside the park -- if the population is below 3,300.
Park biologists last put the population at 4,600 last summer.
Ranchers oppose the proposal because they are worried about diseases and grazing areas.
More than 630 bison had to be removed this winter to keep the numbers down under a 2000 agreement.