Two environmental groups have sued the U.S. Forest Service to halt a logging project along Hebgen Lake south of Ennis, claiming it would harm grizzly bears.

The Alliance for the Wild Rockies and Native Ecosystems Council filed the lawsuit Friday against the Gallatin National Forest and regional Forest Supervisor Tom Tidwell in federal district court in Missoula. The lawsuit aims to stop the Lonesome Wood timber sale, which was planned for 1,570 acres to reduce fire risk to homes built south of Hebgen Lake.

But the area is known as grizzly bear habitat and the U.S. Fish and Wildlife Service did not want it developed when it took grizzlies off the endangered species list, Michael Garrity, AWR spokesman, said in a telephone interview.

“Roads are the number one reason for grizzly bear deaths and they’re building or rebuilding more than five miles of new roads,” he said. “That’s in direct contradiction of what the USFWS asked them to do.” Marna Daley, Gallatin Forest spokeswoman, said officials had not yet seen the complaint and could not comment on it.

The project calls for the construction of 3.7 miles of temporary roads during the logging, and refurbishing another 1.4 miles of old roads. Garrity said that would threaten the bears in the area because it would bring put bears in close contact with people.

“The majority of bear deaths are within 500 yards of a road,” he said.

The groups also said in court records that the logging would further degrade habitat for goshawks and moose, which are already on the decline in the area. The area is designated secure habitat for bears, but that would be lost if the project went forward, he said.

Garrity added that the project wasn’t designed to protect homes because it would include more than 400 acres of old growth forest.

“They’re cutting trees up to 40 inches in diameter and those aren’t the ones that are at risk for fire,” he said.

Reporter Nick Gevock may be reached at nick.gevock@mtstandard.com.