Washington forest campgrounds and trailheads are closing after inspections found root-rot-weakened trees that could fall near visitors

If you've hiked in Washington's Capitol State Forest this year, you may have encountered locked gates. In 2026, the state Department of Natural Resources closed the Margaret McKenny and Middle Waddell campgrounds and trailheads for the summer season. According to DNR's official closure notice, routine inspections found a significant number of trees in the area were infected with a disease called laminated root rot, and officials decided the trees were too hazardous to leave standing near visitors.

A fungus that eats trees from the ground up
Laminated root rot is caused by the fungus Phellinus sulphurascens. Its primary target is Douglas-fir, the tree species that defines much of Washington’s forests. According to a 2013 report by the Washington State Academy of Sciences with the state Department of Natural Resources, the fungus enters a tree’s root through the bark and rots the wood layer by layer, steadily working its way up from underground.

That’s why it’s so hard to see. For years, a tree may appear to be perfectly healthy aboveground, while its root system is quietly falling apart underneath. Once the crown begins to thin or yellow, the damage below is often already severe.

How it actually spreads (and how it doesn't)
This disease doesn't spread through soil stuck to hiking boots or bike tires. According to an overview of laminated root rot in western North America published by the U.S. Forest Service, the fungus is most commonly spread underground when the roots of a healthy tree touch an infected stump or an old infected root left behind after logging. Airborne spores may also be released, but are less important in day-to-day spread.

The report also notes that the fungus is especially severe in young Douglas-fir and other conifers, and that once a pocket is established it can persist for decades because the pathogen survives in old infected roots and stumps. It is most common in the Pacific Northwest, but hardwoods are immune and that diagnosis relies on crown symptoms, root signs and other field indicators rather than soil movement alone.

In short, this is a forest problem, not a foot traffic one. The fungus moves at its own speed, from one tree to another, sometimes over decades, no matter how many people pass by.

Why this particular closure happened
The real danger is not from transmission. It's collapse. A Douglas-fir with a decayed root system loses its hold on the ground, and wind or its own weight are often enough to bring it down, roots and all. The WSAS report noted that trees with green, healthy-looking crowns can still have extensive root rot underneath and be prone to windthrow. That’s why DNR closed the campgrounds in Capitol State Forest this year. Inspectors found enough infected trees that the area was a public safety risk from falling and uprooting trees.

It’s not just about losing timber in the long run anymore. It’s a plea to close a trail before a compromised tree falls on someone standing under it.

The bigger picture for Washington's forests
The fungus has been impacting Washington’s Douglas-fir stands for a long time. The WSAS report said infection centers normally grow at the rate of about a foot a year and that economic losses from the disease throughout the Pacific Northwest range from 5 percent to 15 percent.

The committee brought together nine experts from Washington, Oregon, Idaho and British Columbia, spanning federal, state, university and industry perspectives, to answer DNR’s request for management options. The report then organizes its work around the disease’s economic, ecological and research priorities, including a detailed review of estimated losses and a section on contemporary strategies such as silvicultural and molecular approaches.

What's newer is how directly this underground disease is now colliding with public recreation, as forest managers have to weigh hazard risk against keeping trails open.

What this means if you're planning a trip
If you're headed to a Washington state forest, it's worth checking DNR's recreation alerts before you go, especially in older, mixed-conifer areas. A closure like the one at Capitol State Forest isn't red tape for its own sake. It's arborists buying time to assess and remove genuinely hazardous trees.

The fungus itself isn't going anywhere. But understanding what's actually driving closures like this one, hazardous falling trees rather than any risk from hikers themselves, makes it easier to understand why a trailhead might suddenly be gated off, and why that gate is there for your safety.