BILLINGS, Mont. (AP) — Leaders of American Indian tribes in the Rocky Mountains and Great Plains are signing onto an effort to retain federal protections for grizzly bears in and around Yellowstone National Park.

The U.S. Fish and Wildlife Service is expected to decide this year whether it will move to lift protections for the roughly 1,000 grizzlies scientists say live in the Yellowstone region. The campaign to enlist tribal backing for continued protections — including a prohibition on hunting — is being coordinated in large part by wildlife advocates. Organizers say more than two dozen tribes have signed on through resolutions or other declarations of support.

Grizzlies received federal protections in 1975 after getting wiped out across much of their range. Federal grizzly recovery coordinator Chris Servheen says letters of consultation were sent to four tribes in April but none responded.