Geological Activity Common in Oregon

A landslide is a location where the ground is constantly on the move, part of the natural geology of Oregon, especially along the coast and throughout the Coast Mountain Range. Landslide events are when a new or existing landslide experiences a large pulse of movement. We are continually assessing and taking inventory of unstable slopes. We currently have 4,143 identified unstable slopes along Oregon highways. These landslides affect about 7% of our entire highway system or 495 miles of road.
Our mission is to keep our roads safe and open for travelers. We also recognize the need to make our system more resistant to earthquakes, which can trigger landslides. The effects of climate change make the system even more vulnerable to slope movement.
- ODOT is continually taking inventory of unstable slopes. We currently have 4,143 identified unstable slopes along Oregon highways.
- 69 debris flows
- 2,274 landslides
- 1,899 rockfalls
- The estimated cost to stabilize damage to infrastructure of all inventoried unstable slopes is on the order of $34.5 billion.
- We typically spend around $2.5 million a year on unstable slope mitigation projects and $18.1 million on maintenance repair.
We have placed the worst sites into three primary categories in order of descending severity: “Critical State”, “Immediate Need”, and “High-Priority”. There are 26 Critical State sites, 120 Immediate Need Sites, and 774 High Priority sites leaving 3,309 Medium and Low Priority sites. All of these present some level of risk and are all dangerous regardless of category. It’s just that some of them are more dangerous than others.
At the current funding rate it would take 391 years to address the Critical State sites, 811 years to fix the Immediate Need sites, and 3,950 years to deal with the High-Priority landslides and rockfalls. If we quadrupled the current funding rate, we could address all of the Critical State sites in 30 years.
Below you'll find more information including definitions, what we are doing and what you can do.