Lake Washington Ship Canal begun in 1906, and work began in earnest five years later. The delays in canal planning and construction resulted in the U.S. Navy building the Puget Sound Naval Shipyard in Bremerton, Washington, which is located across the Sound from Seattle. For centuries, people had been dragging boats between the lakes, giving names like "carry a canoe" "sxWátSadweehL" to the crossing points. In 1854 Seattle pioneer Thomas Mercer proposed canals connecting Lake Union and Lake Washington to Puget Sound in a speech at the first Independence Day celebration of the Seattle area's first permanent white settlement, shortly after its founding. Mercer
Puget Sound faults geologic province is the approximately 50 million year (Ma) old marine basalts of the Crescent Formation, part of the Siletzia terrane that underlies western Washington and Oregon. East of Puget Sound the basement of the Cascades province is various pre-Tertiary (older than 65 Ma) metamorphic rock. Somewhere between Puget Sound and Cascades foothills these two geological provinces come into contact. As the juxtaposition of various disparate tectonic structures in northwest Washington requires significant strike-slip movement, it is further expected that this contact will be a major fault. The northern end of the Crescent Formation (aka Metchosin Formation) has been identified