The first of the pontoons for the new SR-520 bridge left Grays Harbor Wednesday morning to begin its journey to Lake Washington.
The pontoon, which is under tow, is expected to reach the Hiram M. Chittenden Locks in Seattle late Saturday night or early Sunday morning.
The trip from Grays Harbor to Shilshole Bay is approximately 260 nautical miles.
The pontoon was built in Aberdeen and is 360 feet long, 75 feet wide, and 29 feet tall.
The new SR-520 floating bridge will require a total of 77 pontoons, including 33 built in Aberdeen and 44 in Tacoma.
You can track the first pontoon's journey online here, just search for vessel "Peter M."
Traffic note - the SR-520 floating bridge and all connected ramps will be closed between Montlake Boulevard in Seattle and Interstate 405 in Bellevue from 11 p.m. Friday, Aug. 10, to 5 a.m. Monday, Aug. 13, while crews demolish the old Bellevue Way Northeast overpass and dig a 25-foot-deep trench to install a culvert beneath all lanes of the highway.