The Milwaukee Road's Pipestone Pass

(Please note that the latter two photos here do not feature Pipestone Pass Tunnel.)

Another of the many impressive engineering feats accomplished during the construction of the Milwaukee Road's Pacific Coast Extension was its crossing of the Continental Divide at Pipestone Pass, which was along the eastern edge of the Rocky's foothills in a range known as the Pioneer Mountains. Interestingly, the pass was not far from the Jefferson River Valley and to keep grades reasonable the railroad's engineers built the equally impressive Vedome Loop, which was only a few miles to the east. Today, like the loop Pipestone Pass Tunnel remains quiet as trains have not traversed the route in more than 30 years.

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 GN and NP 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 Pipestone Pass when in operation please click here to view the collection of Ron Nixon housed at the Museum of the Rockies, Montana State University. (Please note that the first photo featured on this page, courtesy of the museum, includes their corresponding image number so that you may quickly and easily find more information about it from their website.)

Survey work on this section of line between Lombard and Butte began in 1904 with surveyors determining that the lowest grade route over the Pioneer Mountains was through Pipestone Pass at the Continental Divide. Construction of the tunnel and right-of-way was carried out by the McIntosh Bros. and by 1908 a temporary line had been completed between Three Forks and Butte although the tunnel itself was yet to be completed making for a tortuous climb over Pipestone for about a year.

However, the work was not easy. Loose and solid granite rock along the way made grading very difficult resulting in the route's opening being slightly delayed and costing more than anticipated. The Pipestone Pass Tunnel, officially known as "Tunnel #11" on the Milwaukee Road and located at Milepost 1505.5, itself was completed and opened in 1909 (general boring and drilling had been completed during 1907 and 1908). By the early 20th century most railroad tunneling projects were being constructed entirely of concrete to reduce maintenance costs and increase strength and Pipestone Pass Tunnel was no different (actually, all of the tunnels along the Pacific Extension were built this way).

The tunnel sat an elevation of 6,347 feet and was about a half-mile in length at 2,290 feet. Overall, the route between Butte and Three Forks through the mountains ranged in grade from 1.66% to 2%, which was quite good considering roughly ten miles east of the tunnel the mountains drop away to Jefferson River Valley. To keep the grade manageable engineers and surveyors designed the impressive 3-mile Vendome Loop.

Pipestone 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. A similar thanks goes out to the Museum of the Rockies at Montana State University for allowing Ron Nixon's historic collection of the Milwaukee Road in the west to be featured here.)

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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