2026 project timeline
Chuckanut Creek – Milepost 246
- Apr. 2026
I-5 bypass road at Chuckanut Creek built with nightly single-lane closures. Old Samish Road closes. - May 2026
SB I-5 shifts to Old Samish Road. NB I-5 shifts onto bypass road. Work begins on SB bridge and half of NB bridge. - June 2026
Work on SB and half of NB bridge continues. - July 2026
SB I-5 traffic shifts onto original configuration on new bridge. NB I-5 shifts onto the portion of the new bridge. - Aug. 2026
Work begins on other half of NB bridge and Old Samish Road bridge. - Sept. 2026
Work on NB and Old Samish bridges finishes. - Oct. 2026
NB I-5 and Old Samish Road return to original configuration on new bridge.
Unnamed Tributary to Lake Creek – Milepost 246
- May 2026
Unnamed tributary to Lake Creek bypass road construction begins with nightly single-lane closures. - June 2026
NB I-5 shifts onto SB I-5, while SB I-5 shits to SB I-5 off-ramp to North Lake Samish for work on NB culvert. - July 2026
NB I-5 shifts to original alignment. SB I-5 remains on off-ramp to North Lake Samish for construction of SB culvert. - Aug. 2026
SB I-5 shifts to original alignment. SB I-5 on- and off-ramps to North Lake Samish remain closed while new ramps are built. - Sept. 2026
Construction of new North Lake Samish on- and off-ramps finishes and all lanes of NB & SB I-5 open to traffic.
Unnamed tributary to Lake Creek: Two new, larger culverts
Unnamed tributary to Lake Creek will have a single culvert that crosses under both directions of I-5 (milepost 246). The culvert will be built in two phases, using traffic configurations similar to what is done in 2025. The southbound I-5 on- and off-ramps to N Lake Samish Drive (Exit 246) will also be reconfigured and relocated as part of this work.
Chuckanut Creek: Three Bridges
Chuckanut Creek bridges will be built using a phased construction approach and bypass roads to divert traffic around the work areas. All three bridges will be built and opened to travelers in 2026. Stream restoration work will follow in 2027.
Old Samish Road closure – April 2026
A portion of Old Samish Road will close for up to seven months in order to construct the Chuckanut Creek bridge. Travelers will be provided a signed detour around the closure.
