Tuesday's ruling from the 9th U.S. Circuit Court of Appeals blocks the federal government's effort to lift protections on about 600 threatened grizzlies in Montana, Wyoming and Idaho.
Two members of the three-judge panel criticized government wildlife officials for a "damn-the-torpedoes approach" to removing protections.
Some grizzly bears rely on whitebark pine nuts as a key food source. Beetle infestations brought on by a warmer climate have killed huge swaths of the trees at high elevations in the Yellowstone region.
Government biologists argue grizzlies can adapt and find other food sources.