Minnesota Department of Transportation

511 Travel Info

Historic Bridges

Oliver Bridge (Bridge 6544)

Oliver Bridge (Bridge 6544)

Oliver Bridge

See features of the bridge

History and significance

The Oliver Bridge is a double-deck, Warren truss swing bridge constructed in 1910. The swing span (disabled) rests on a center-bearing pivot mechanism anchored to a reinforced-concrete center pier, with steel approach viaducts on each side. The upper deck consists of a series of parallel plate girder spans. The lower deck is carried by steel stringers.

The Oliver Bridge spans the St. Louis River between Duluth and the village of Oliver, Wisconsin. The upper deck connected the Spirit Lake Transfer Railway in Minnesota with the Interstate Transfer Railway in Wisconsin. The lower deck, opened in 1917, carries State Highway 39/Wisconsin Highway 105. The bridge is significant for its association with transportation of iron ore, steel, and other goods, and as an example of a bridge fabricated by the American Bridge Company. Additionally, the bridge is significant because it represents a unique design solution to meet challenging site conditions and has an exceptional main span length that is well beyond the normal maximum length of steel truss railroad bridges constructed at the time.


City of Duluth (St. Louis County)
Latitude, Longitude: 46.65667942, -92.20167258

Bridge features

Oliver Bridge

Innovative design of a swinging, double-deck, Warren through/deck truss main span with rail traffic above and vehicular traffic below, created to meet challenging site conditions and federal regulation. This feature includes a center-pivot bearing mechanism for the
swing span.

Oliver Bridge

Design and construction of the double-deck, steel approach viaduct spans created to accommodate challenging site conditions and heavier loads.