BILLINGS, Montana - Federal officials have identified 20 parcels of public lands in Oklahoma and nine other states they say could be suitable for bison relocated from Yellowstone National Park.

The Oklahoma locations include the Chickasaw National Recreation Area near Sulphur and Wichita Mountains Wildlife Refuge near Lawton.

Both locations currently have bison. The US Department of Interior says the Chickasaw National Recreation Area has 10 bison and the Wichita Mountains Wildlife Refuge has a herd of 640 bison.

Yellowstone National Park had roughly 4,600 bison at last count.

The population periodically spills into neighboring Montana, triggering large-scale slaughters of the animals to prevent the spread of disease.

A pilot program to relocate Yellowstone bison has struggled to overcome livestock industry opposition in Montana.

If such a program were made permanent, federal officials say it could be up to a decade before more animals were relocated.

In May, the state of Montana said two Oklahoma tribes offered to take a group of bison from Yellowstone National Park that went through an experimental program to establish new herds of the animals.

The Associated Press contributed to this report.