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Motorboat, Sammamish Slough Race, Redmond, April 9, 1952
Photo by Stuart Hertz, Courtesy MOHAI (PI26528)

Sammamish Slough Race

During the early years of pioneer settlement in the 1870s and 1880s, the Sammamish River (also known as the Sammamish Slough) was the primary transportation route from Lake Washington and Lake Sammamish to Bothell and Woodinville, located along the river between the north ends of the two lakes.

On March 4, 1934, the first Sammamish Slough Race was held on the Sammamish River, which flows from Redmond on Lake Sammamish to Kenmore on Lake Washington in northern King County. Within a few years, the motorboat race grew into a large annual event, attended by tens of thousands who marveled at the thrills and the spectacular races.

The river was on average 30 feet wide, but in some places, it was as narrow as 12 feet. There were 63 curves along the roughly 13-mile river route, and it was virtually a rite of passage for a racer to end up in the water. The race was usually held once a year in April, and it continued to expand in the 1950s.

By the early 1950s there were six different classes of boats participating, and this doubled to 12 in the 1960 race. Children as young as 8 were allowed to race, though only in separate heats held and after the main event. Races in the early 1950s still focused on the fastest one-way time in upstream heats between Lake Washington and Lake Sammamish.

Does the Sammamish Slough Race still exist?

Given the dangerous conditions and the lack of protection, it’s fortunate that there weren’t any fatal accidents. It seems equally astonishing that both racers and spectators accepted the risks of such a sport. Unfortunately, the Sammamish Slough Race quickly died out starting in 1976 when a spectator was hurt by an out-of-control boat and the race insurance became too expensive. However, the Slough Race came back in the form of the Kenmore Hydroplane Cup event which made its grand return on April 11, 2014. The 6th annual Kenmore Hydroplane Cup was scheduled on April 6, 2019.

The Descendants of the Sammamish Slough Race

Nowadays, whenever people go to the Sammamish River, they won’t find fast boats speeding down the river. Instead, they will find the Kenmore Rowing Club, a non-profit rowing club based out of the new Kenmore Boathouse located at Rhododendron Park, along the Sammamish River near the public boat launch in Kenmore, Washington. The Kenmore Rowing Club is an organization that provides rowing programs to people of different ages. Inglemoor High School in Kenmore also has a rowing program that started in 2017 and the team practices on the Sammamish River.


  • Kenmore history timeline: Kenmore Heritage Society website
  • Kenmore By The Lake, A Community History
  • Kenmore Community Club

A couple kayaking in the Sammamish River, February 26, 2022
Photo by Arvin Shrestha

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