Bridges and Tunnels: Focuses on the East Central region. Includes forum.
Historic Bridges of the Midwest: Database which also contains news and images. Also covers facilities outside of the core region.
Hobbies and Diversions: Includes Bridges Of Minneapolis/St. Paul, Bridges Of The Upper Mississippi River, Bridges Of The Lower Mississippi River, and the North American Cable Stay Bridge Registry, which consist of photographs and data.
National Bridge Inventory Database: Form on a private website which retrieves information about individual structures, culled from the Federal Highway Administration National Bridge Inventory.
National Bridge Inventory Study Foundation: Gives details on certain structures and includes state summaries.
Roads and Bridges: Various views from Boston, Massachusetts; Louisville, Kentucky; Minnesota; and Wisconsin.