140 years ago, Northern Pacific Railway finally opened its “great iron” bridge spanning the Missouri River between Bismarck and Mandan for traffic on October 21, 1882, nearly ten years after the railroad reached Bismarck only to abruptly stop construction due to bankruptcy stemming from the Panic of 1873. Its importance on Bismarck, and the railroad, cannot be underestimated and its construction was a feat of engineering for the time.
What many may not know is that tunneling the river was also being considered in 1880. There were multiple reasons for considering a tunnel instead of a bridge, chiefly cost and time. It was estimated that an iron bridge of “great height and length,” then planned to be nearly two miles long, would cost $1.5 million (more than $40 million today) as opposed to $600,000-$750,000 for a tunnel – about half the cost, which could also be completed quicker. There were also concerns over foundation grounding and common ice jams. The tunnel would have begun its westward decent at the Sheridan House, where today’s historic depot now stands, and extended almost 13,000 feet – one of the longest in the world at the time – to a depth of twenty feet below the riverbed.
It seems that Northern Pacific was never fully committed to the idea of a tunnel, however, and quickly abandoned the idea in favor of a bridge. The tunnel concept was pitched to Northern Pacific by Mister H. Clark, a railroad contractor who previously built the impressive Boston waterworks tunnel and selfishly sought the Bismarck project.
Another common misconception is the date itself. Nearly every source, including very legitimate sources, cite the bridge’s completion as October 1883 when in fact, it was one year earlier… in October 1882. Why this common inaccuracy? Most likely it’s because the official golden spike ceremony marking Northern Pacific’s railroad completion occurred in 1883, and the bridge is often directly associated with the railroad’s completion.
Indeed the bridge’s completion was a milestone event for the railroad. By this time, only about 300 miles of track were unfinished between Minnesota and the Pacific coast, over the difficult Rocky Mountains, and most of it was already graded. Work was being completed at an astonishing rate of about 1.5 miles per day. Traffic on the western line was steadily increasing, partially propelled by rapid development of the Yellowstone valley.
This illustration from Harper’s Weekly on March 15, 1879 depicts the railroad’s crossing of the Missouri River on ice.
Source: Institute for Regional Studies, NDSU, Fargo (Folio 102.TrR34.1a)
The Lack of a bridge spanning the mighty Missouri River impeded full usage of the nearly-completed northern transcontinental railroad. Weather permitting, trains could be ferried across the river in warmer months, and temporary tracks laid across the ice during the winter – an achievement that received national attention. Neither of these were ideal, or guarantees.
Impact on Bismarck
Lack of a completed bridge, and its unknown final location, impeded Bismarck’s early development and financial investment. Buildings were still wooden and intended to be easily relocated as there was doubt that a bridge would ever be completed – or where.
Many have been deterred from making Bismarck their permanent residence on account of the uncertainty of this crossing, arguing that wherever the road crossed the river, there would be the coming city. Many business men have been restrained from constructing substantial brick buildings on account of this same uncertainty. -Bismarck Tribune; September 24, 1880.
This all changed with the bridge’s opening, and corresponding railroad soon after. Now, Bismarck was highlighted as the important city it was originally envisioned to be. One newspaper of the time hailed Bismarck as the “Omaha of the northwest.”
Northern Pacific Railroad Bridge; 1883.
Credit: Bismarck Veterans Memorial Public Library (Capital City Memories: 5d-1)
Investment into Bismarck immediately increased at a rapid pace. Massive brick building blocks were erected, the biggest of which was the Bismarck National Bank – known as the Raymond Block – on the northwest corner of Third Street and Main Avenue. Another, the Gothic-style Dakota Block on the northeast corner of Second Street and Main Avenue still stands today. Most importantly, Bismarck may never have become Dakota Territory’s capital in 1883 without the completed railroad and bridge.
Bridge Work Commences
Bismarck, founded as Edwinton in 1872, was always intended to be the railroad’s crossing, although where this crossing would precisely occur was up for debate. Originally, it was planned to be at the mouth of the Heart River at Fort McKeen (later Fort Abraham Lincoln). The original crossing location was planned because it was located at a narrower, shallower bend of the river for a shorter bridge, both lengthwise and height-wise, resulting in a lower cost. Later studies indicated the ground was not strong enough to support an iron train bridge at this location.
There are other reasons cited for why the crossing, and corresponding railroad was relocated north, including land claim disputes.
Where it was ultimately built, estimates of the day called for a two-mile bridge. River diking on the west bank narrowed the river channel to about 1,200 feet and the resulting bridge was only 1,426 feet long; divided into three main 300-foot spans and two shorter 100-foot spans. It was reported to stand seventy feet above the low water mark.
The bridge was indeed shifted even further north than the road itself, which attributes to the sharp northern bend just west of historic Camp Hancock that we still see today. This was done to drive the pier pilings into “blue clay.” One consideration would have positioned the bridge four or five miles north of the city.
The railroad reached Bismarck from the east in June 1873, but construction halted soon after and wouldn’t resume for six years when the City of Mandan was founded as a railroad workcamp for westward construction. Official planning for the river’s crossing came the following year.
The first serious planning occurred in April 1880. Northern Pacific studies miles of riverfront to determine the best crossing. One contender was the original planned crossing, at Fort Abraham Lincoln, where the river narrowed to less than 1,000 feet wide. However, the ground was weaker here so it was decided to narrow the river artificially where stronger footings to support a bridge could be placed. Also, diking the river’s western bank cost less than rerouting the railroad south to take nature’s advantage of Fort Lincoln’s crossing.
By June, the bridge’s final location was more-or-less decided, within less than three hundred feet of the existing line. This location wouldn’t require considerable reconstruction of the line and contained suitable grounding. Its design was decided by the following month. Northern Pacific officially approved the bridge’s construction on December 16, 1880.
Building the Bridge
Bridge Completed; Bismarck Tribune, October 27, 1882
Constructing the bridge involved three major elements: River rectification (including diking), the bridge itself (piers and superstructure), and the approaches on each end.
Dike work commenced almost immediately, in fall 1880, completing its foundation. They constructed a wired willow mattress for the dike, which is a technique to counter erosion, in this case made from willows to revegetate the shore. In January 1881, Cottonwood logs were placed onto the mattress to wall in stone and frozen earth for the dike.
The severe winter season of 1880-1881 resulted in regional flooding, by some accounts the severest witnessed to this day, and ice rushed down the river with “unusual violence.” The dike remained mostly intact until river current eroded about two hundred feet during the spring and summer. More impactful, the navigable river channel shifted west of the dike toward the Mandan side.
It was unsure which channel would become permanent, so engineers planned for both possibilities until it gradually shifted back to the east. In May 1881, engineers unsuccessfully attempted to close the west channel with a pile bridge. When the river receded, another attempt commenced in July and the pile bridge was completed by August. Channel silt completely filled in the west channel by early winter.
Bridge Superstructure and Piers
The bridge deck was built to be fifty feet above the high-level river mark. This impressive height was attributed to the high bluffs to the east and to compensate for unpredictable river levels caused by ice jams. The deck rests on four granite piers, which were built for the dual purpose as ice breakers through its steel-covered points placed against the current.
Georgy Morison was the chief engineer and superintendent of the bridge’s construction. In January 1881, Northern Pacific awarded contracts for the bridge itself… Illinois-based Saulpaugh & Company to construct the granite piers, and Detroit Bridge and Iron Works for the superstructure. The Saulpaugh company subcontracted building and submerging the caissons to Chicago-based Rust and Coolidge. Quarrying for the piers began that April, from multiple sources in Minnesota. Ground was first broken on May 12 with work for the east abutment. Foundation work for the easternmost pier began the following day and was completed on November 20.
The caissons used to construct the piers in the river channel itself were 74x26x17 feet, made of pine framing with three-inch oak plank encased with 82,000 pounds of iron. The working chamber, where laborers would work in the depths of the river to build the piers, was seven-feet high. The caissons were built on shore before getting towed into position to be submerged using 500 cubic yards of concrete placed above the working chamber. Air was pumped into the working chamber to displace water for workers.
Testing the Northern Pacific Railroad Bridge; 1882. Testing the Northern Pacific Railroad Bridge; 1882.
The second caisson, launched on August 6, 1881, proved particularly difficult to submerge since a sandbar had formed between the shore and intended river placement. Thus, the caisson was launched down stream a quarter-mile and towed against the current to its destination.
The approach spans on each end were completed by May 1882. The first of the longer bridge span was erected between the easternmost piers, with the first iron placed on July 27, 1882 and the span completed on August 12. The second span was completed on September 9, and the final span on October 7.
By this point, only the deck floor and some minor finishes were needed.
The Bridge Today
BNSF Railway Bridge in 2009
As of 2022, Bismarck’s 140-year-old train bridge is still in use by Northern Pacific’s successor, BNSF Railway. Unfortunately, it seems this won’t be the case much longer as BNSF has for years planned to replace the historic structure, despite efforts to save it.
While the original piers still support today’s bridge, its original iron superstructure, including the deck and trusses, was replaced with steel in 1905 to handle heavier loads. The resulting appearance became greatly altered with more circular shapes of the trusses.
