Most of us think of wildfire in Washington state as something that happens east of the mountains. There’s a reason for that: more than 99 percent of wildfires in the last 40 years have been east of the Cascade Crest.

But forest fires are a natural, though rare, occurrence on the west side of the mountains as well. These verdant forests don’t immediately seem like burnable material. But, with the right conditions, these areas can also experience wildfires. Years without fire allow trees and understory brush to grow and accumulate significant biomass, which can produce large, severe wildfires.

Brian Harvey, assistant professor in the UW School of Environmental and Forest Sciences, is studying fires in Washington that burn on the west side of the Cascade Crest. He and his research team are building on evidence that suggests Western Washington has a history of large wildfires, each burning hundreds of thousands of acres. We might not be familiar with them, because most happened centuries ago.

“Being able to understand these systems is really critical to our ability to manage them as a society, and make really smart decisions about how we’re going to manage forests,” said Harvey. “That’s particularly important as the human footprint continues to expand.”

Gathering data on west side fires may help determine risks for people who have built homes and communities near wooded areas. It might help in planning how to protect watersheds, and in thinking about forest products and recreation that are part of our economy and culture.