Slides close Sun Road; flood watch is issued

Heavy rain triggered rock slides, mud slides and blocked culverts Friday along Glacier National Park's Going-to-the-Sun Road.

The central portion of the park's main highway was closed, and forecasts for more rain raised concerns about flooding and possible road failures.

A weather station on Flattop Mountain north of Sun Road recorded 2.9 inches of rainfall for the 24-hour period ending at 9 a.m. Friday. Just a couple of hours earlier, park road workers encountered fallout from the rain along Sun Road.

There were mud slides east of Logan Pass near Jackson Glacier Overlook and near the West Side Tunnel, where there was a major road failure in the spring 1995.

Culverts were clogged with mud and rock in several locations along the road's alpine stretch, resulting in water running across the road at Logan Creek west of the Loop and below the East Side Tunnel.

A boulder the size of a small car landed on the road between the Loop and Haystack Creek just west of Logan Pass.

"I think it's safe to say that Logan Pass probably won't be open to through traffic probably for a few days," Glacier Public Affairs Officer Amy Vanderbilt said.

Sun Road is closed between Avalanche Creek on the west side and Rising Sun on the east side.

"We will have personnel working on this all weekend," Vanderbilt said. "The boulder is going to require blasting to remove it. We're hoping that will happen today or Sunday at the latest."

The National Weather Service on Friday issued a flood watch for Glacier National Park, west of the Continental Divide, due to a forecast predicting more heavy rain. The watch says there is potential for another 4 inches of rain possible through this afternoon.

"It certainly has our attention," Vanderbilt said of the potential flooding.

Workers collected fallen rock from the road and used it to form temporary water bars to help divert water across the road in some places, such as an area below the West Side Tunnel where water had undercut the uphill side of the road, Vanderbilt said.

In spring 1995 a big chunk of Sun Road collapsed just below the West Side Tunnel after soils below the road became saturated because of a blocked culvert.

That incident prompted park officials to seriously consider the potential for major failures on Sun Road. Then-Superintendent David Mihalic embarked on a campaign to rebuild the historic highway's alpine stretch, a project that is expected to begin in 2007.

Vanderbilt noted that the last time there was flooding in the fall was in 1989. There was considerable flooding in the Middle Fork Flathead River drainage on the park's southern border, she said, but there were no flood-related problems on Sun Road.

Vanderbilt said construction equipment was being staged at St. Mary "just in case there is flooding in that area." There is a history of Divide Creek flooding in the St. Mary area.

Reporter Jim Mann may be reached at 758-4407 or by e-mail at jmann@dailyinterlake.com