- The Montlake Cut, between the Montlake and University District neighborhoods in Seattle, connects Lake Washington and Lake Union as part of the Lake Washington Ship Canal. When it was completed in 1916, it marked the realization of a 62-year-old idea to link the lakes with Puget Sound, creating a freshwater harbor in Seattle and a waterway connecting Seattle’s shipping harbor in Elliott Bay with the resource-rich interior of King County. The canal boosted economic development on the lakes and helped reduce flooding in the Duwamish River valley (its former outlet), but it also had far-reaching environmental and cultural consequences.