Grizzly bears in eastern Idaho were returned to federal protection under the Endangered Species Act by U.S. District Judge Donald Molloy.

    The ruling reverses a decision made by the U.S. Fish and Wildlife Service in 2007 that transferred control of grizzly bears in the Yellowstone ecosystem from the federal government to the states of Idaho, Wyoming and Montana outside of Yellowstone and Grand Teton national parks. Molloy said the conservation strategy on which the Fish and Wildlife Service based its delisting, was not enforceable and did not meet the requirement of the act to ensure rules were in place to protect bears after delisting.

    "Because the service admits that the conservation strategy is unenforceable, the strategy was not properly considered in the service's evaluation of existing regulatory mechanisms," Molloy wrote.

    Molloy also said the service did not adequately consider the impacts of global warming and other factors on whitebark pine nuts, a key grizzly bear food source.

    Killing a threatened species under federal law carries a maximum jail sentence of one year in prison, a fine of $100,000 and possible restitution. That penalty had remained in place in central, northern or western Idaho - west of Interstate 15 - since bears there remain protected as threatened under the Endangered Species Act.

    But killing a grizzly bear in eastern Idaho, where the predator is delisted, carries a maximum six months in jail, a fine of $1,000, the loss of hunting privileges for up to three years and possible civil penalties. Idaho was beginning to consider what it would take to reopen hunting on the bears that were first listed as threatened in 1975.

    Since then the population has risen from an estimated low of 136 bears to more than 500.

    But the Natural Resources Defense Council, the Sierra Club, the Center for Biological diversity and others sued saying it was too early to delist.