Malheur National Forest in Eastern Oregon the Humongous Fungus.

A lot of people have probably heard about Malheur National Forest because of the January 2, 2016, when an armed group of far-right extremists seized and occupied the headquarters of the Malheur National Wildlife Refuge in Harney County, Oregon. I'm not going to talk about that and this post is for the television series The Last of Us fans. The blue whale is the biggest animal on Earth, but it’s not Earth’s biggest life form. No, the blue whale pales in comparison to the actual largest living thing on the planet: the humongous fungus (Armillaria ostoyae), also known as honey fungus. This fungus is located in Malheur National Forest and is covers an area of about three-and-a-half-square-miles. Now that is truly humongous. It is also estimated to be some 8,000 years old and may weigh as much as 35,000 tons.

Picture taken off the internet.

At that kind of size, you would imagine that the humongous fungus would be easy to spot. You would be wrong. That’s because it’s almost completely underground for most of the year. It only pops up when it comes time to reproduce. That is usually during the month of October.

See, the part of a fungus you’re probably most familiar with is the mushroom cap. But that’s only one specific part of the fungus, and in most species, it’s the only part that appears above ground. It’s called a fruiting body, and it’s a reproductive organ. I’ll let you take a minute to absorb the fact that pretty much every mushroom you’ve ever eaten has been fungus genitalia.

Anyway, this goes for the humongous fungus too. Its mushrooms only peek above ground when it’s time to make more humongous funguses.

Over hundreds and thousands of years, the world's largest living organism has slowly infected, killed, eaten, and engulfed countless trees and shrubs unlucky enough to be in its path. Honey fungus is, after all, an infamous killer in the forest world. Its black rhizomorphs are like highways that allow white rot to travel from host to host. The "white rot" associated with Armillaria infects trees and shrubs by encircling, attacking, and ultimately killing their roots. While this is happening, rhizomorphs continue onward, always seeking another host.

While many parasites found in nature require a living host, Armillaria is a facultative saprophyte, so it can survive and live off of its hosts long after it's killed them. This allows for almost limitless expansion without the need for self-regulation that's required by parasites that depend on a living host.

Over months or years, the attacked host dies. The Armillaria is especially pathogenic to softwoods like Douglas-fir (Pseudotsuga menziesii), true firs (Abies spp.), and Western Hemlock (Tsuga heterophylla). This makes eastern Oregon a great location for it to survive.

The fungus' progress can be tracked by the expanding areas of dead and dying trees. The Humongous Fungus was discovered by taking samples from all the known infected trees in the park and comparing their fungal DNA.

In diverse forests, fungi kill and feed on only the weakest trees. But what can happen with a monoculture of trees (all the same types of trees planted together in large areas) is that disease or weather can weaken all of them at the same time. When this happens, it allows fungi like Armillaria to take out entire forests at once.

How to get here: If you are coming from western Oregon you would have to take Route 26 East past Prairie City Oregon and from Eastern Oregon it would be Route 26 West to right after the little town of Bates Oregon. See map above. You have to understand that you are taking Forest Service Roads to get here and they are also known as logging roads. It is a long curvy road and there are a lot of potholes. To get detailed directions to get here I would stop at the Ranger Station located at 327 SW Front St, Prairie City, OR 97869.

Remember the best time to come is in the Autumn and it is typically the forest’s busiest season (popular for elk hunting), and many campgrounds fill to capacity on weekends. In late October and early November, the needles of western larch trees turn a vibrant shade of yellow throughout the forest. Be sure to wear blaze orange if you plan to be in the woods during hunting season.