BILLINGS — U.S. government attorneys filed notice Friday that they are appealing a court ruling that restored protections for grizzly bears in the Northern Rockies and blocked plans to hold the first public hunts for the animals in decades.

The legal move challenges a September ruling from U.S. District Judge Dana Christensen in Montana. He reversed a 2017 decision that had lifted threatened species protections for more than 700 bears in and around Yellowstone National Park.

The ruling came as Wyoming and Idaho were on the cusp of hosting their first public hunts for grizzly bears in the Lower 48 U.S. states since 1991.

Wildlife advocates and the Crow Indian Tribe had asked Christensen to intervene. They persuaded the judge that the species remains in peril due to continued threats from climate change and habitat loss.

But federal biologists contend Yellowstone-area grizzlies have made a full recovery after a decades-long restoration effort. They want to turn over management of the animals to state wildlife agencies that say hunting is one way to better address rising numbers of bear attacks on livestock.

The population has rebounded from just 136 animals when they were granted federal protections in 1975. Grizzlies in recent years have moved into many areas where they were absent for decades.

That’s meant more dangerous run-ins with people such as a Wyoming hunting guide who was killed earlier this month in an attack by a pair of grizzly bears.

U.S. Fish and Wildlife spokeswoman Jennifer Strickland referred questions about the case to the Department of Justice, which did not immediately respond to an emailed request for comment.

Already pending before the 9th Circuit were appeals from several parties that intervened in the case on behalf of the Fish and Wildlife Service — the states of Idaho and Wyoming and the National Rifle Association and Safari Club International.