SR 503 - 3 Miles West of SR 503 Spur - Slope Stabilization - Complete May 2018

Why did WSDOT perform emergency slope stabilization work on the hillside adjacent to SR 503 near Speelyai Recreation Road?
Following a winter with record rainfall, on Monday, March 13, 2017, a portion of the hillside in east Cowlitz County, slid down, carrying trees and debris over the roadway. 

Due to debris blocking both directions of the roadway and because of unstable rock above, WSDOT determined the highway was unsafe for travel and closed the road.

To stabilize the slope, crews worked in a top down approach, and stabilized an estimated 20 million pound rock slab that had separated from the hillside.

On Friday, March 31, 2017, crews began working to access the slope, remove the large rockface and stabilize the slope. Emergency contractor crews began blasting work which resulted in clearing the massive rock slab above the highway.

Long-term stabilization work included rock anchoring and bolting was done in the spring of 2018, and continued into the fall.

The End Result
This project reduced the potential for falling rocks and trees, which would have created a hazard on the roadway.

Needs & benefits

This project stabilized the slope alongside SR 503, removed rocks and debris from the hillside, the highway and shoulder and reestablished the connection in both directions of SR 503, near Cougar.

This project reduced the possibility of emergency closures and traffic delays due to rock slides.



  • The total final cost of this project was $2.4 million


Vancouver WSDOT Area Engineer

Tamara Greenwell, WSDOT communications

Trooper Will Finn, WSP Public Information Officer

Commercial haulers using Forest Service roads as an alternate should contact:
Aldo Aguilar, 360-891-5113 for road use permits and Shea Becker, 360-891-5166 for bridge permits.