BNSF Scenic Subdivision

The Salmon Bay Bridge, also known as Bridge No. 4, is a Strauss Heel-trunnion single-leaf bascule bridge spanning across Salmon Bay and connecting Magnolia/Interbay to Ballard in Seattle, Washington. The bridge is located just west of Commodore Park. It carries the main line of the BNSF Railway on its way north to Everett and south to King Street Station and Seattle's Industrial District.

The Salmon Bay Bridge, which is located west of the Hiram M. Chittenden Locks, is the last bridge to span the Lake Washington Ship Canal before it becomes Puget Sound. Built in 1914 by the Great Northern Railway, it has an opening span of 61 meters and has two tracks. Additionally, vessel clearance when lowered is 13.1 meters at mean high tide, and up to 15.3 meters at low tide.BNSF Railway initially planned to replace the Salmon Bay Bridge with a new vertical-lift bridge, but chose to repair failing components of the existing bridge following consultation with the local community.