Yellowstone 16
A herd of bison graze in the Lamar Valley in Yellowstone National Park. REUTERS

Once upon a time, Bison roamed across the American plains in the tens of millions. Now, just 30,000 remain in the wild and roughly 3,700 of those are in Yellowstone National Park.

Park officials have proposed that as many as 360 migrating bison be shot by hunters in Montana, captured for slaughter, or shipped elsewhere this winter under a new plan that seeks to provide an alternative to the indiscriminate slaughters of previous years.

Officials are considering selective culls to help reduce the park's bison population from 3,700 to 3,000, according to a report obtained by The Associated Press.

The proposal comes amidst rising pressure from Montana officials like Governor Brian Schweitzer to rein in the size of the park's iconic herds.

Earlier this month, some Montana residents expressed public and livestock safety concerns related to migrating bison. Ranchers claim the bison compete for grazing space and spread diseases like brucellosis.

Brucellosis can cause miscarriages in pregnant animals and has been eradicated nationwide, except in the Yellowstone region. More than 3,600 Yellowstone bison were removed over the last ten years to prevent the spread of the disease.

Regardless, many say that the bison should be allowed to roam freely.

Under the new proposal, officials hope to steer clear of the mass slaughters conducted in winters past. In 2008, for example, more than 1,700 bison were removed or killed as the herds left the park in droves during the harsh winter to seek food at lower elevations.

According to Montana state officials, hunting is the preferred method for population control. Schweitzer said Yellowstone officials must be willing to open their borders for hunting because in milder winters, animals rarely cross out of the park.

These things have to have some give and take, Schweitzer told the AP. The buffalo doesn't know where the line is when it leaves the park. We end up taking care of the oversupply of bison because they aren't managing their population within the park.

In years without major migrations, Yellowstone's bison populations have grown relatively unchecked, setting the stage for large-scale slaughters when the populations peaked.

Under the new draft proposal, 200 female bison, 50 calves, and 50 yearlings from the park's northern herd could be shot, relocated, or slaughtered. An additional 20 to 30 bulls from the northern herd and 30 bulls from the central herd could be removed during a late-winter hunt.