A grizzly bear has attacked a federal biologist during a surprise encounter at a research site in Montana's Centennial Valley.

U.S. Fish and Wildlife Service spokesperson Joseph Szuszwalak said the biologist, who was not named, was treated for serious bite wounds Wednesday before being released from a hospital in Rexburg, Idaho, the Missoulian reported.

The biologist heard a noise in the brush while monitoring a sage grouse research project and saw two grizzly bears less than 100 yards (300 feet) away, Szuszwalak said. One bear stood up while the other charged.

The biologist used bear spray until the animals ran off. Other Fish and Wildlife Service staff nearby helped escort the biologist to safety.

The attack occurred in the Red Rock Lakes National Wildlife Refuge west of Elk Lake in Beaverhead County.

Both Montana Department of Fish, Wildlife & Parks and Idaho Department of Fish and Game investigators are reviewing the incident.

Recreationists and people who work outdoors are urged to be aware of surroundings, carry bear spray, travel in groups and follow U.S. Forest Service food storage orders, which have been in effect for public lands in Montana since March 1.

Source: AP