Three researchers with USGS mapped a history of 215 different landslides across 64 percent of a 86-square-mile area between Prindle and Carson in Skamania County.
“I think most of us think about the Earth being pretty static, but depending on the time scale you’re looking at, it’s all really dynamic,” said Thomas Pierson, a research hydrologist at the Cascades Volcano Observatory in Vancouver.
The landslides have occurred over a broad time line. About a fifth of the slides the researchers observed are more than 1,000 years old. Around a dozen occurred in the last two decades or are currently moving.
Read more at The Columbian.