BILLINGS, Mont. (AP) — Grizzly bears are spreading into new areas of the U.S. Northern Rockies, expanding from remote wildernesses and into low-level farmland amid a legal fight over proposed hunting.

New government data from grizzly population monitoring show bruins in the Yellowstone area of Montana, Wyoming and Idaho expanded their range by about 1,500 square miles (3,900 square kilometers) over the past two years.

Frank van Manen with the U.S. Geological Survey says that means more bears on private lands, where they can encounter humans and attack livestock.

Wyoming and Idaho officials proposed grizzly hunts last year, but they were blocked by a judge's ruling.

Government attorneys on Friday asked an appeals court to overturn part of that ruling. The case could take months or even years to decide.