As bridge gets a facelift, a look at its history

The weather outside the plastic sheet is in the single digits, but inside it's comparatively toasty as Rockwell Wenzel of Tamietti Construction of Great Falls works on the concrete of the Going-to-the-Sun Road's Avalanche Creek Bridge.

While the bridge sees thousands of motorists and pedestrians a year, few folks get the view Wenzel has. He'+s under the bridge working on a concrete span that dates back to the mid-1930s. The idea is to make the new concrete look like the old concrete and that takes some doing.

The original concrete forms used 7 1/2-inch planking - an odd dimension by today's standards. The forms also left a distinct line in the concrete. To meet the historical standards in the new concrete, Tamietti had lines sawn into the modern plywood forms they were using.

The new work is largely cosmetic, it has virtually no structural bearing on the bridge, which has an interesting history.

According to historian Kathryn Steen, almost as soon as the Sun Road was completed in 1933, the Park Service and the Bureau of Public Roads (which is now the federal Highway Administration) had plans to reconstruct 20 miles of the road on the west side and about eight miles on the east side.

Those sections were narrower, with tighter curves and log structures.

Reconstruction of the west side began in early 1935. Over the next three construction seasons, the road saw improvements from West Glacier to about one mile east of Logan Creek.

Today, Sun Road reconstruction costs millions - rock walls alone run about $1,300 a foot. But then, W.K. Trippet of Whitefish had the low bid of $48,000 on a series of contracts to improve the road, including the Avalanche bridge and two bridges over Snyder Creek.

The original bridge over the idyllic creek was a log structure built in 1923 by contractor Laux Gardner. Trippet first shored up that bridge and then began work on the new one.

Trippet's bridge was masonry and box concrete. Trippet completed two piers and one abutment of the new bridge in the fall of 1935. Winter weather shut down operations Nov. 3. They finished the work the following spring and summer. Traffic first used it Aug. 14, but it was completely finished by Sept. 1. They also modified the channel of the creek and hand-laid rip-rap upstream from about 125 feet.

A 1925 agreement between the Park Service and BPR required that structures blend into the landscape and use construction materials from the Park.

Many west-side contractors at the time quarried rock along the side of the road near the Haystack Creek Culvert.

Pay at the time was 60 cents an hour for unskilled labor and 75 cents an hour for -semi-skilled+ labor. The pay for skilled workers was $1 an hour, but Steen said Trippet paid his skilled labor $1.15 an hour.

Once work on the new concrete is finished, the masonry that meets it will be re-done. Work on other bridges is also planned for this winter, including an unnamed bridge to the east and the Logan Creek bridge.

Work will continue for the next few weeks if the weather holds. Fall and winter are generally ideal times to complete bridge work because the water is low.

In this case, Avalanche creek was diverted to one side of the bridge while crews work on the other side. Once that side is complete, the creek will be diverted to the other side of the 22-foot long bridge.

The work on the bridge is part of a larger effort to reconstruct the road from Avalanche Creek to the west side tunnel.