The BNSF Railway Bridge (originally Northern Pacific) is a historically significant train bridge spanning the Missouri River between Bismarck and Mandan. It was the first bridge to cross the upper Missouri River.
Related Article: Building Northern Pacific’s “great iron” train bridge over the Missouri River, and its impact
While the rail line reached Bismarck in 1873, the Panic of 1873 forced construction to halt for six years. Towards the end of 1878, work resumed to extend the railroad west of the Missouri River, as well as a bridge.
The general construction contract was let in January 1881. It was designed after the Plattsmouth bridge, connecting Iowa and Nebraska, and engineered by the same architect… George Morrison.
It finally opened in October 1882*, nearly ten years after the railroad first reached Bismarck. While the ceremonial golden spike took place the following year, in western Montana, the bridge effectively completed the line.
In April 1905, Northern Pacific let a contract to replace the original superstructure, comprising mostly iron, with steel that could handle heavier loads. When first built, train loads of four hundred tons were the norm, but that weight load had roughly quadrupled and the original superstructure was deemed inadequate. After some modifications, the original structure was re-purposed for a bridge spanning the Columbia River at Pasco, Washington.
The original granite piers, which still support the bridge to this day, were shored up. In particular, the easternmost pier had been an ongoing problem, shifting towards the river.
Most recently, in 2017, BNSF Railway announced intentions to replace the historic bridge. In an effort to save the icon, a local resident took up a petition with hopes to turn it into a walking bridge. The National Trust for Historic Preservation placed the bridge on its annual list of the top 11 most endangered historic places in 2019.
In April 2023, BNSF was granted the finally approval to begin bridge replacement. The replacement bridge will built to the north of the existing historic structure, which is likely to be demolished. Dirt began moving in July. Piledriving bridge supports was performed in summer 2024. The entire project is expected to take four years to complete.
*Note: Numerous sources cite 1883 as the year the bridge completed, but newspaper articles of the era clearly prove it was 1882.
