[2] The bridge is a through arch design and crosses the Great Bras d'Or channel of Bras d'Or Lake, connecting Boularderie Centre, Boularderie Island on the south side with New Harris, Cape Breton Island on the north side.

The bridge is a crucial link in the Trans Canada Highway between Sydney and Baddeck, carrying more than 7,500 vehicles a day in peak periods.

[5] The steel structure is supported on tall reinforced concrete piers, armoured with cut stone at the waterline.

For political reasons, it was decided to place the bridge halfway between the two ferry services on account of an outcry by communities fearing the loss of their transportation links.

Forty years of wear and tear from traffic as well as exposure to wind and salt spray necessitated a major overhaul of the Seal Island Bridge.

This has resulted in considerable savings in the amount of truss reinforcement required, while providing sufficient mass and stiffness for damping purposes.

On April 20, 2004, it was announced the Seal Island Bridge Reconstruction Project had won the Lieutenant Governor's Award for Engineering Excellence.

The Department of Transportation and Public Works shared the honours with consultants CBCL Limited of Halifax for the major overhaul of the province's third largest bridge.