Salmon Bay is that part of the Lake Washington Ship Canal

Lake Washington Ship Canal

The Lake Washington Ship Canal, which runs through the City of Seattle, Washington, connects the fresh water body of Lake Washington with the salt water inland sea of Puget Sound. The Ship Canal includes a series of locks, modeled after the Panama Canal, to accommodate the different water levels...

--which passes through the city of Seattle, linking Lake Washington

Lake Washington

Lake Washington is a large freshwater lake adjacent to the city of Seattle. It is the largest lake in King County and the second largest in the state of Washington, after Lake Chelan. It is bordered by the cities of Seattle on the west, Bellevue and Kirkland on the east, Renton on the south and...

 to Puget Sound

Puget Sound

Puget Sound is a sound in the U.S. state of Washington. It is a complex estuarine system of interconnected marine waterways and basins, with one major and one minor connection to the Strait of Juan de Fuca and the Pacific Ocean — Admiralty Inlet being the major connection and...

--that lies west of the Fremont Cut

Fremont Cut

The Fremont Cut is a part of the Lake Washington Ship Canal—which passes through the U.S. city of Seattle, Washington, linking Lake Washington to Puget Sound—that connects Lake Union to the east with Salmon Bay to the west. It is long and wide. The center channel is wide and deep...

. It is the westernmost section of the canal, and empties into Shilshole Bay

Shilshole Bay

Shilshole Bay is the part of Puget Sound east of a line drawn northeasterly from Seattle's West Point in the southwest to its Golden Gardens Park in the northeast. On its shores lie Discovery Park, the Lawtonwood section of the Magnolia neighborhood, the neighborhood of Ballard, and Golden Gardens...

, which is part of Puget Sound. Because of the Hiram M. Chittenden Locks

Hiram M. Chittenden Locks

The Hiram M. Chittenden Locks are a complex of locks that sit at the west end of Salmon Bay, part of Seattle's Lake Washington Ship Canal. They are known locally as the Ballard Locks after the neighborhood to their north...

, the smaller, western half of the bay is salt water, and the eastern half is fresh water (though not without saline contamination—see Lake Union

Lake Union

Lake Union is a freshwater lake entirely within the Seattle, Washington city limits.-Origins:A glacial lake, its basin was dug 12,000 years ago by the Vashon glacier, which also created Lake Washington and Seattle's Green, Bitter, and Haller Lakes.-Name:...

). Before construction of the Ship Canal, Salmon Bay was entirely salt water.

East of the locks, Salmon Bay is spanned by the Ballard Bridge

Ballard Bridge

The Ballard Bridge, also known as the 15th Avenue Bridge, is a double-leaf bascule bridge in Seattle, Washington, United States. It carries 15th Avenue NW over Seattle's Salmon Bay between Ballard and Interbay. Built in 1917, it has an opening span of and a total length of . It was added to the...

, a bascule

Bascule bridge

A bascule bridge is a moveable bridge with a counterweight that continuously balances the span, or "leaf," throughout the entire upward swing in providing clearance for boat traffic....

 bridge

Bridge

A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...

 that carries 15th Avenue traffic between Ballard

Ballard, Seattle, Washington

Ballard is a neighborhood located in the northwestern part of Seattle, Washington. To the north it is bounded by Crown Hill, ; to the east by Greenwood, Phinney Ridge and Fremont ; to the south by the Lake Washington Ship Canal; and to the west by Puget Sound’s Shilshole Bay. The neighborhood’s...

 and Interbay

Interbay, Seattle, Washington

Interbay is a neighborhood in Seattle, Washington in the United States consisting of the valley between Queen Anne Hill on the east and Magnolia on the west, plus filled-in areas of Smith Cove and Salmon Bay...

. West of the locks, it is spanned by the Salmon Bay Bridge that carries the BNSF Railway

BNSF Railway

The BNSF Railway is a wholly owned subsidiary of Berkshire Hathaway Inc., and is headquartered in Fort Worth, Texas. It is one of seven North American Class I railroads and the second largest freight railroad network in North America, second only to the Union Pacific Railroad, its primary...

railroad tracks.