Lake Union () is a freshwater

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

located entirely within the city limits of

Seattle Seattle ( ) is the most populous city in the U.S. state of Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the 18th-most populous city in the United States. The city is the cou ...

, Washington, United States. It is a major part of the

Lake Washington Ship Canal The Lake Washington Ship Canal is a canal that runs through the city of Seattle and connects the fresh water body of Lake Washington to the salt water inland sea of Puget Sound. The Hiram M. Chittenden Locks accommodate the approximately diff ...

, which carries fresh water from the much larger

Lake Washington Lake Washington () is a large freshwater lake adjacent to the city of Seattle, Washington, United States. It is the largest lake in King County, Washington, King County and the second largest natural lake in the state of Washington (state), Was ...

on the east to

Puget Sound Puget Sound ( ; ) is a complex estuary, estuarine system of interconnected Marine habitat, marine waterways and basins located on the northwest coast of the U.S. state of Washington (state), Washington. As a part of the Salish Sea, the sound ...

on the west. The easternmost point of the lake is the Ship Canal Bridge, which carries

Interstate 5 Interstate 5 (I-5) is the main north–south Interstate Highway System, Interstate Highway on the West Coast of the United States, running largely parallel to the Pacific coast of the contiguous U.S. from Mexico to Canada. It travels thro ...

over the eastern arm of the lake and separates Lake Union from Portage Bay. Lake Union is the namesake of the neighborhoods located on three of its shores: Eastlake, Westlake and South Lake Union. Notable destinations on the lake include

Lake Union Park Lake Union Park is a park located at the south end of Lake Union in Seattle, Washington in the South Lake Union neighborhood. The park is owned by the City of Seattle and operated by Seattle Parks and Recreation. The park property was gradua ...

, the Museum of History & Industry (MOHAI), and the Center for Wooden Boats on the southern shore and Gas Works Park on the northern shore. The Aurora Bridge (officially the George Washington Memorial Bridge) carries State Route 99 over the western arm of Lake Union. The Aurora Bridge is so named because it carries Aurora Ave N down the western side of the lake. Lake Union's westernmost point can be considered the Fremont Cut, which is located just west of the Aurora Bridge and is spanned by the Fremont Bridge. The Fremont Bridge carries Fremont Ave N between the neighborhoods of Fremont and Queen Anne and separates Lake Union from the rest of the Lake Washington Ship Canal to the west.

Description

Lake Union is a natural lake in

that lies north of the city's

central business district A central business district (CBD) is the Commerce, commercial and business center of a city. It contains commercial space and offices, and in larger cities will often be described as a financial district. Geographically, it often coincides wit ...

. It is fully surrounded by urban neighborhoods and highways. Lake Union is the smaller of the two major lakes in Seattle, the other being

. Part of the

system, water flows into the lake from

through the Montlake Cut, and out via the Fremont Cut on its way to

. Before the construction of the

canal Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface ...

, Lake Union emptied into Salmon Bay via a creek which followed roughly the same course as the Fremont Cut does today. Because of the connection via the Hiram M. Chittenden Locks to the salt water of

, the water is brackish to a certain extent, which increases in the summer as the inflow rate from

decreases and the locks open more frequently for pleasure craft.

History

glacial A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

lake, its basin was dug 12,000 years ago by the Vashon glacier, which also created

and Seattle's

Green Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 nm. In subtractive color systems, used in painting and color printing, it is created by a com ...

, Bitter, and Haller Lakes.

Name

In Lushootseed, the lake is known as , meaning "small lake." It is the diminutive form of the name of Lake Washington, . In

Chinook Jargon Chinook Jargon (' or ', also known simply as ''Chinook'' or ''Jargon'') is a language originating as a pidgin language, pidgin trade language in the Pacific Northwest. It spread during the 19th century from the lower Columbia River, first to othe ...

, the trade language primarily used in the 19th century, it is called ("small water"). Lake Union received its present name from

Thomas Mercer Judge Thomas Mercer (March 11, 1813 – May 25, 1898) was a pioneer associated with the early history of Seattle. Seattle's Mercer Street and Mercer Island, Washington, Mercer Island in Lake Washington bear his name. Biography Early life Merc ...

, who in 1854 correctly predicted that

s would someday join Lake Washington to

in a "union of waters."

Pre-development

Lake Union was formed by the recession of the Vashon Glacier approximately 14,000 years

before present Before Present (BP) or "years before present (YBP)" is a time scale used mainly in archaeology, geology, and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because ...

Geography

Several Seattle neighborhoods take their name from the lake: Eastlake, Westlake, Northlake, and South Lake Union; and three major streets are named in relation to it: Westlake Avenue, which runs along its western shore from

Downtown ''Downtown'' is a term primarily used in American and Canadian English to refer to a city's sometimes commercial, cultural and often the historical, political, and geographic heart. It is often synonymous with its central business district ( ...

to the Fremont Bridge; Eastlake Avenue, which runs along its eastern shore from

Cascade Cascade, or Cascading may refer to: Science and technology Science * Air shower (physics), a cascade (particle shower) of subatomic particles and ionized nuclei ** Particle shower, a cascade of secondary particles produced as the result of a high ...

to the University District, and Northlake Way, which runs along its northern shore from the University District past Gas Works Park to the edge of Fremont.

Uses

Boeing The Boeing Company, or simply Boeing (), is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, and missiles worldwide. The company also provides leasing and product support s ...

began production on Lake Union in 1916, there had a hangar assembled the company's first product B & W Seaplane. Shipyards, wharves, and sawmills have also dotted the shore.

Floating homes

Floating homes line the east and west sides of Lake Union. In ''

Sleepless in Seattle ''Sleepless in Seattle'' is a 1993 American romantic comedy film directed by Nora Ephron, from a screenplay she wrote with David S. Ward and Jeff Arch. Starring Tom Hanks and Meg Ryan, the film follows a journalist (Ryan) who becomes enamored ...

'', the character played by

Tom Hanks Thomas Jeffrey Hanks (born July 9, 1956) is an American actor and filmmaker. Known for both his comedic and dramatic roles, he is one of the most popular and recognizable film stars worldwide, and is regarded as an American cultural icon. Ha ...

lived on one of these homes.PacificNorthwestMovies.com
,

Recreation

Lake Union's proximity to and scenic views of the central Seattle and University District skylines make it a popular recreational spot. Seaplane operated by Kenmore Air and Seattle Seaplanes land and take off from the lake throughout the day. Pleasure boats from

pass through on their way to

. The Center for Wooden Boats holds a yearly wooden boat festival, while the annual Seattle Boat Show at the end of January demonstrates seacraft for sale on actual waters, in addition to its displays in the concourse of

Lumen Field Lumen Field is a multi-purpose stadium in Seattle, Washington, United States. Located in the city's SoDo neighborhood, it is the home field for the Seattle Seahawks of the National Football League (NFL), Seattle Sounders FC of Major League ...

. The world-famous Duck Dodge sailboat races are run on Lake Union each Tuesday during the summer. Rowers in sweep and sculling boats use the lake year-round. Paddleboarding and kayaking are also popular on this lake.

Parks

Gas Works Park is the largest park on Lake Union and the most popular for Seattleites and visitors. It is the venue for summer concerts and Seattle's major

Fourth of July Independence Day, known colloquially as the Fourth of July, is a federal holiday in the United States which commemorates the ratification of the Declaration of Independence by the Second Continental Congress on July 4, 1776, establishing th ...

fireworks Fireworks are Explosive, low explosive Pyrotechnics, pyrotechnic devices used for aesthetic and entertainment purposes. They are most commonly used in fireworks displays (also called a fireworks show or pyrotechnics), combining a large numbe ...

show. Other parks ring the lake, clockwise around the compass from Gas Works which is nearly due north: North Passage Point Park, South Passage Point Park, Fairview Park, Terry Pettus Park, and South Lake Union Park.

Competitive rowing

Lake Union is home to several rowing centers and teams, including Holy Names Academy Crew, Lake Union Crew, Lake Washington Rowing Club and Pocock Rowing Center, all members of USRowing. Also rowing out of bodies of water attached to Lake Union are the Seattle Rowing Center and the Conibear Shellhouse, serving the

Washington Huskies The Washington Huskies are the college athletics in the United States, intercollegiate athletic teams that represent the University of Washington, located in Seattle. The school competes at the National Collegiate Athletic Association (NCAA) N ...

Transportation

Seaplane base

Lake Union is home to two seaplane bases: Kenmore Air Harbor Seaplane Base , and Seattle Seaplanes , located one nautical mile (1.85 km) north of the