Project overview
Contractor crews working on behalf of WSDOT will replace the culvert crossings under State Route 20 at an unnamed tributary to Skagit River (milepost 94) and Olson Creek (milepost 105) in Marblemount. The current culverts are barriers to fish passage, and they will be replaced with structures that will allow them to pass beneath SR 20.
What to expect
SR 20 traffic is using a two-lane shoofly (or temporary detour) as contractor crews construct the bridge. Travelers should expect occasional flagging stoppages for equipment and material mobilizations.
Section 1 – Unnamed tributary to Skagit River (milepost 94) – in progress
Traffic is currently back on SR 20. Travelers should expect occasional flagging stoppages for equipment and material mobilizations.
Section 2 – Olson Creek (milepost 105) – Construction is scheduled to begin in the summer of 2024.
During construction travelers can expect daytime single-lane closures for utility relocation. Travelers should expect flaggers to alternate traffic through a sling lane on SR 20. A four-day, full-closure of SR 20 is expected in September 2024. The dates have not been set, but a detour around the closure will be available.
