Project overview
On Tuesday, Feb. 23, 2021, due to roadway settlement caused by heavy rainfall, both directions of State Route 401 (also known as the Lewis and Clark Trail Highway) between the Astoria-Megler Bridge and Naselle were closed.
In spring 2021, emergency contractor crews were able to reopen a single-lane of the highway near milepost 5.0, allowing travelers access through the area by alternating intermittently through a single-lane with an automated traffic signal.
In late summer 2023, contractor crews will begin work to stabilize the slope, improve drainage and repair the roadway. Additionally, as part of this project, contractor crews will make improvements to the Knappton Boat Launch located off of SR 401 along the Columbia River near milepost 4.0. Contractor crews will regrade the gravel boat launch site and parking area and replace vandalized signs.
What to expect
**UPDATE 10-7-2023**
Crews have completed the work to rebuild the highway, and both directions of SR 401, near Knappton, are fully open.
When construction begins, contractor crews will utilize alternating single lane closures with flaggers. Once slope stabilization, road repair and drainage improvement work begins, crews will fully close the highway for up to five weeks. During the full road closure, travelers will follow a signed detour using SR 4 and US 101.
As part of this project, contractor crews will make improvements to the Knappton Boat Launch located off of SR 401 along the Columbia River. Contractor crews will regrade the gravel boat launch and parking area and replace vandalized signs.
In late summer 2023, contractor crews will begin work to stabilize the slope, improve drainage and repair the roadway. Additionally, as part of this project, contractor crews will make improvements to the Knappton Boat Launch located off of SR 401 along the Columbia River near milepost 4.0. Contractor crews will regrade the gravel boat launch and parking area and replace vandalized signs.
