The Milwaukee Road's St. Paul Pass Tunnel

One of the Milwaukee Road's most famous tunnels along its Pacific Coast Extension was located in the Bitterroot Mountains at St. Paul Pass along the border of Idaho and Montana. One of the tougher sections of the route (between Butte and St. Paul Pass) to survey and build due to its remoteness it took crews nearly two years to lay out all possible routes before engineers and the railroad eventually chose the route over the pass and begin construction. The tunnel, nearly a mile high in elevation and over a mile in length, became unique in that part of it lay in the state of Montana while the other part lay in the state of Idaho. Today, St. Paul Pass Tunnel, also known as Taft Tunnel, has not seen a train in more than 30 years although it is now part of the "Route of the Hiawatha" rail/trail.

In 1901 the first surveying work began and it was estimated the more than 1,400-mile western extension would cost the railroad around $45 million adding more than 25% to its total system mileage. However, four years later this number was readjusted to $60 million. What made the extension so terribly expensive was partly due to the right-of-way costs. Unlike the Great Northern and Northern Pacific the CM&StP was not given free government land grants and had to both purchase all of its land from private landowners as well as take over a number of small, new, or floundering railroads across the region.

Amazingly, in just three short years the entire extension had been completed and on May 19, 1909 a Golden Spike was driven at Garrison, Montana commemorating the opening of the new route. For an excellent pictorial history of the building of the Pacific Coast Extension and images of St. Paul Pass Tunnel when in operation please click here.

Surveying this section and the area it covered is somewhat staggering. The railroad estimated that for every one mile of grade which was ultimately chosen as part of the main line up to 4.5 miles was surveyed and documented. In total, between Butte and St. Paul Pass some 1,040 miles was surveyed with the actual main line covering those two points being only 230 miles in length.

Contract work for the building of the St. Paul Pass Tunnel was done by Winston Brothers Company of Minneapolis, Minnesota, which also handled much of the grading and construction between Missoula and the pass with the primary subcontract work carried out by contractors W.B. Cronk, A.D. McDougal & Company, Stewart & Welch, and Street & Lusk.

Heading west from Missoula grading began in July 1906. Around this same time work was also started on the tunnel with its approaches completed in 1906 although heavy boring work did not begin until late 1907. Overall the gradient of St. Paul Pass Tunnel was kept at a manageable 1.7% while its overall length to span the Bitterroots was 1.66 miles! The tunnel was officially completed in December, 1908 giving the Milwaukee Road its second-longest tunnel across its Pacific Coast Extension.

For the railroad, which numbered its tunnels from east to west, the structure at St. Paul Pass was officially listed as #20. The tunnel also became known as Taft Tunnel due to its close proximity to the tiny hamlet of Taft, Montana near the state line. However, the railroad came to know this location as East Portal, as it was the location of one of the company's substations once the line was electrified a few years after the tunnel's opening.

After the Milwaukee Road abandoned its Pacific Coast Extension in March, 1980 the tunnel sat dormant and empty for more than 20 years before it was officially "rededicated" on June 23, 2001 as part of the "Route of the Hiawatha" rail/trail. Today, the St. Paul Pass Tunnel sees thousands of hikers and bikers annually. For more information about riding the trail please click here. Also, for more reading about the operations of St. Paul Pass Tunnel please click here.

St. Paul Pass Tunnel Specifications

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(A deep thanks to Mr. Michael Sol for providing much of the historical material and information used to research the pass.)

Also, to learn more about the Milwaukee's famous Olympian Hiawatha and the other Hiawatha services consider purchasing a copy of The Milwaukee Road's Hiawathas from authors Brian Solomon and John Gruber. The 160-page book details the entire 36-year history of the trains from 1935 through 1971 and is filled with photographs. If you're interested in a general history and overview of the Milwaukee's premier passenger services you will definitely enjoy this book. If you're interested in perhaps purchasing either (or both) of these books please visit the links below which will take you to ordering information through Amazon.com, the trusted online shopping network.

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