I-94 (Blue Water Br.) / St. Clair River

MDOT Historic Bridge St. Clair County Blue Water Bridges

County: St. Clair

City/Township: Port Huron

Location: I-94 (Blue Water Br.) / St. Clair River

Year Built:  Original span: 1938; second span: 1997

About this Bridge:
The original Bluewater Bridge linking Port Huron, Michigan and Sarnia, Ontario was completed in 1938 at a cost of $4 million, financed jointly by the State of Michigan and the Province of Ontario. This steel cantilever bridge has a main span of 871 feet, anchor arms 326 feet long, and approaches consisting of deck girder spans and two deck truss spans adjoining the anchor arms on both the American and Canadian sides. The American approach spans are 2283 feet in length, while the Canadian approach is 2657 feet long, giving the bridge an overall length of 6463 feet. It is 38 feet wide, providing a roadway of 32 feet and two sidewalks. Each of the two main piers consists of two calssons 26 feet in diameter, whit eight foot dredging wells. These were sunk to rock 95 feet below water level.

This first span provides clearance of 150 feet above the heavily traveled St. Clair River. It was designed by the firm of Modjeski and Masters and their Canadian associates, the firm of Monsarrat and Pratley. The American Bridge Company fabricated and erected the main span, the Wisconsin Bridge and Iron Company erected the American approaches, and the superstructure for the Canadian approach span was built by the Sarnias Bridge Company.

For more on the building and operation of both spans, see this history from our Blue Water Bridge history page. See also this history from the Canadian Blue Water Bridge Authority.