The Bear Gulch Tunnel Fire has been contained.

“Current fire activity is limited to inside the Bear Gulch Railroad Tunnel, where unstable structural conditions have prevented firefighters from safely accessing and extinguishing remaining heat sources,” reported the Caribou-Targhee National Forest Service in a press release.

Residents reported flames and smoke in January, and, since that time, the tunnel has been closed to the public.

While the fire activity is limited, the Forest Service wrote that the small fire might still produce some smoke.

“Interior heat pockets may continue to produce smoke that can be seen or smelled near the tunnel’s entrances,” it stated.

Workers recently removed numerous weakened structures near the tunnel’s south entrance. Doing so, allowed the Forest Service to reduce the fire closure area.

“The remaining closure includes the area immediately north of and adjacent to Forest Service Trail 001 — from the fence on the west side of the railroad tunnel to the fence on the east side. The closure area extends 300 yards uphill from the trail and includes the tunnel and surrounding terrain,” it reported.

It wasn’t known what caused the tunnel fire, but it’s been suggested it could have been human-caused.

The tunnel is only about 100 yards long. About 10 years ago, a section of it collapsed.

The tunnel was built around 1906. The train transported everyone from Yellowstone National Park tourists to grade school children. It frequently passed through Ashton, often serving as residents’ morning alarm clocks.

By 1960, the last Ashton passenger train traveled to Yellowstone National Park. Snowmobilers continued to drive through the tunnel, but about 15 years ago, officials attempted to close access to the tunnel. Despite “no trespassing” signs, people still ventured through it anyway.

As for now, the Forest Service is urging residents to avoid the tunnel.

“The structure remains extremely unstable and poses significant safety hazards,” it reported.

For additional information contact the Ashton-Island Park Ranger District at 208-652-7442.