Washington is one of the most landslide-prone states in the country , and Western Washington’s steep slopes and wet weather put it especially at risk. This January was the fourth-wettest in state history and was followed by a set of February storms intense enough that Lt. Gov. Cyrus Habib declared a state of emergency in Western Washington on Feb. 5.

Those sudden storms are only expected to get worse as the climate shifts, making the Pacific storm belts known as “atmospheric rivers” more frequent. By the end of the century, the most intense daily rainstorms in Western Washington are expected to bring 22% more rain.

“The models are pretty clear that at least for our region, those atmospheric river events will become more common,” says Guillaume Mauger, research scientist with the University of Washington Climate Impacts Group.

Climate science can’t fully explain the future behavior of landslides; there are too many variables for scientists to have a clear sense for what will change. But “the one thing that’s pretty straightforward,” says Alison Duvall, assistant professor of earth and space sciences at the University of Washington, “is that more water, more intense water, more fire, or more intense logging is tipping things towards the abundance or increase of landslides.”

In 2011, WSDOT’s Climate Impacts Vulnerability Assessment Report found that climate change is expected to exacerbate current problems with flooding, landslides and coastal erosion. WSDOT does not keep track of the number of landslides on state highways, but it has identified some state routes as being more vulnerable than others to extreme weather events. County roads like Fairfax Forest Reserve Road aren’t included in the assessment.

Some of the most vulnerable highways are those in the mountains and at the base of steep slopes. SR 20, for instance, which runs adjacent to the North Cascades and closes for winter because of snow, might be closed just as often in coming decades even if the snow disappears. According to the report, fewer snow closures “may be offset by an increase in landslides because of rain events on slopes that are not protected by snow.”

Climate change will affect much of SR 410, too: Running parallel to the White River on one side and the Naches River on the other, the road is highly susceptible to flooding, high winds and slides.

“Everyone that I talk to at the closure is understanding — especially the people that are familiar with the area,” says State Trooper Rick Johnson, after responding to slides that blocked SR 410 near Greenwater. “There’s been slides there before, but the local residents are pretty resilient.”

“All of us pretty much know each other,” says Greenwater Fire Chief Paul Sowers. “We send out the call via word of mouth that we need some help filling sandbags.”

Although the highway was officially closed from Feb. 6 to Feb. 10, Sowers noted that a path had been cleared by Feb. 7 for medical emergencies. During the closure, Sowers kept the community updated via Facebook posts and led convoys out of the area for those who needed to buy groceries.

At the same time, further south, a landslide across SR 706 cut off Dennis Day and the other residents of a small neighborhood just a few hundred yards west of the Nisqually entrance to Mount Rainier National Park.

“The main thing that we’re doing is knocking on doors,” says Day, a volunteer firefighter and fire commissioner of Lewis County’s Fire District 17. A number of the area’s residents are in their 80s, and some people who weren’t physically able to serve as first responders nevertheless pitched in as volunteers, showing up with shovels, trucks and backhoes.

“This is the most flooded I've seen it,” Day says.

He calls his neighborhood an “island community”: While technically part of Lewis County, the people there are almost entirely dependent on neighboring Pierce County Fire District 23 for emergency services. The Lewis County seat of Chehalis is about two hours away in ideal conditions, so Day emphasizes that it’s the responsibility of people who live there to check in on each other.

“We don’t all have to go to each other’s birthday parties, but we have to make sure the roads are open,” Day says.

Ultimately, the response to the SR 706 slide brought together local residents, WSDOT emergency response teams, volunteer firefighters from two counties, Pierce County Emergency Management, the Forest Service and Mount Rainier National Park.

Matt Medford, fire chief and only full-time employee of Pierce County’s Fire District 23, says that keeping the community safe would have been more complicated without Mount Rainier National Park as a neighbor. The park has its own law enforcement and emergency services staff, and they offered emergency medical treatment to any residents outside the park boundaries who had been isolated by the slide.

In the mountains of Washington, the road network can be sparse, leaving some communities with only one way in and out. A 2014 Forest Service report on Climate Change Vulnerability and Adaptation in the North Cascades noted that on the roads around the North Cascades and Mount Rainier “the loss of a segment of trail or road can leave large areas inaccessible for long periods depending on the extent of damage and availability of resources for repair.”

The road network through Washington’s mountains is largely inherited from 19th century routes that took the easiest way across the passes. Because terrain limits highway routes, the roads often follow the path of least resistance through valleys or low points. Gravity, water and mudslides follow that same path.

“Because we have beautiful mountains and lakes and the Sound, we have a very tricky and narrow corridor of transportation,” says Duvall. “Our rail and many of our road corridors are in the most landslide-susceptible positions.”