- Bitter Lake is a neighborhood in Seattle, Washington, United States, named after its most notable feature, Bitter Lake. It was a mostly natural forest of Douglas-fir and Western Redcedar, inhabited by Native Americans, until the late 19th century. Development especially picked up when the Seattle-to-Everett Interurban streetcar reached the lake in 1906. A sawmill operated in the area until 1913, when most of the trees had been cut down.