The Odd Angle of the Stone Arch Bridge Explained: How It Saved St. Anthony Falls
The historic Stone Arch Bridge is one of Minneapolis’ most iconic landmarks. Spanning the Mississippi River with its elegant arched design, the bridge captures the eye of visitors and locals alike.
But have you ever wondered why this 142-year-old bridge crosses the river at such an odd diagonal angle? The story behind its unique orientation is a fascinating tale of ingenious engineering and careful planning.
Overcoming a Railroad Conundrum
In the 1880s, Minneapolis faced a significant railroad problem. With no efficient way to bring goods and passengers into downtown from the rail tracks on the east side of the river, the city turned to James J. Hill, owner of the main rail connection between Minneapolis and St. Paul, for a solution. The goal was to construct a Union Depot near the intersection of Nicollet and Hennepin avenues, allowing trains to easily access the heart of the city.
An Ingenious Angled Design
To mitigate the risk of catastrophic erosion and ice jams, Hill’s engineer, Col. Charles C. Smith, proposed building the bridge below St. Anthony Falls, just upstream from where Hill’s tracks ended near present-day Dinkytown. By crossing the river at a diagonal angle, with a gentle 6-degree curve at one end, trains could reach the planned Union Depot while minimizing disruption to the riverbed.
Speed and Permanence in Mind
Unlike the fragile timber railroad bridges of the era that forced trains to crawl, Hill wanted a permanent structure that could handle full-speed rail traffic. The Stone Arch Bridge’s sturdy limestone and granite design, combined with its curve, supported efficient, high-speed movement that set it apart in its time.
Legacy of Innovation
The Union Depot opened in 1885, and the Stone Arch Bridge quickly became an integral part of Minneapolis’ transportation network. Its unusual angle, born from a need to protect the falls and the riverbed, stands as a testament to the city’s early engineering ingenuity.
Know Before You Go: Visiting Today
The bridge is open to pedestrians and cyclists. Check city or park updates before visiting for any temporary maintenance closures. Popular access points include Mill Ruins Park on the west side and Father Hennepin Bluff Park on the east side. Sunset is prime time for skyline photos.
Nearby Stops to Add to Your Walk
Plan a loop with stops at the Mill City Museum, St. Anthony Main, Water Works Park, and the Upper St. Anthony Falls Lock & Dam overlook. Grab coffee on Main Street or a patio seat along the river.
Respecting the River and Falls
Stay on marked paths, especially near the falls and ruin areas. Spring and early summer bring high water and slick surfaces. In winter, expect ice and wind on the span; dress warm and wear traction if paths are icy.
Best Photo Spots on and Around the Bridge
Top spots include Mill Ruins Park on the west bank for arches and skyline at sunset and blue hour; mid-span on the bridge for symmetry and leading lines, but brace for vibrations; the St. Anthony Main riverwalk on the east bank for morning light and long exposures; Water Works Park for an elevated view of the bridge, lock, and falls; Father Hennepin Bluff Park trails for lower angles near the water and tripod-friendly dusk shots; and the Third Avenue Bridge area for compressed skyline views with a telephoto from the west side.
