SEATTLE – The Oso landslide tragedy killed 43 people more than two-and-a-half years ago, but the cause of that landslide has never been cleared up.
David Montgomery, professor of geomorphology at the University of Washington, said there’s no evidence logging played a role in the slide, although without a proper analysis it’s hard to tell. What is more concerning for the public is how the Department of Natural Resources approaches logging on potentially unstable slopes. He said DNR is looking to generate money for state coffers through timber harvest sales and also regulate harvesting, all within the same branch of the agency.
“So, within that one branch of that one division of state government, you have an agency that’s charged with the awkward and, at times, conflicted mandate of both promoting a practice and regulating a practice,” Montgomery explained. “And, in my view, it’s good practice to try and separate those two potential interests.”
Montgomery suggests the agency move assessment of forest practices to the landslide-hazard program in DNR’s geologic division. He also wants the state to convene an independent study of the cause of the Oso landslide. Timber lands generate millions of dollars for Washington state each year, and that money goes toward building schools and boosting rural counties.
Hilary Franz, the next state lands commissioner, has expressed concern about the economic impact on small forest owners of over-regulating logging.
The reasons landslides occur are complicated. Along with factors such as how much rain a slope gets and whether it is considered “dormant,” historical and recent logging can play a role in reactivating landslides. But Montgomery said if one follows DNR’s current forest-practices manual for landslide hazard assessment, fine distinctions are not taken into account.
“You basically would walk through to the conclusion that if something is not already active, if it’s a dormant landslide, they essentially routinely approve logging on it from what I can tell on my perch outside the agency,” he said. “And I think that some higher level of analysis would simply be prudent to be done prior to approving logging on ancient landslides.”
Montgomery said the agency has embraced what he called the “faulty logic” that if an unstable slope was harvested in the past and didn’t fail, it won’t fail in the future. More thorough analysis is needed, he said, to ensure landslides don’t become reactivated because of logging.

Eric Tegethoff
Eric Tegethoff is a journalist covering the Northwest. Eric has worked as a reporter for KBOO, XRAY FM, and Oregon Public Broadcasting in Portland, Oregon, as well as other print and digital news media. In 2012, Eric traveled to North Dakota to write about the Bakken region oil boom. He's also worked at a movie theater, as a campaign canvasser and quality assurance at a milk packaging factory. Eric is originally from Orlando, Florida. He graduated from the University of Florida in 2010.