Forest Thinning

The “Hydro-axe” in action taking down a tree. PC: Corey Corbett.

You may occasionally notice temporary closures on some of the trails due to fuels reduction. The Forest Service has contracted with a company to improve the health and safety of the forest by a process called “fuels reduction” where excess trees are ground up as mulch. In order to accomplish this, they use a machine called a “Hydro-Axe”, which resembles a giant weed whacker on steroids. This intimidating looking machine will pulverize an entire tree in seconds and fling debris for 100’s of yards in every direction. While they are operating, the crews close nearby trails in order to keep people out of the line of fire. You don’t want to be in the vicinity while they are operating. Please observe the trail closures as they are for your own safety.

The thinning process serves multiple purposes. It thins the trees and allows more sunlight in to make the remaining trees healthier, and it reduces fuelwood, thereby making future fire less intense. Normally mother nature handles this job in the form of forest fires. When they happen frequently enough, forest fires are relatively small and don’t burn as fiercely, and they actually make the forest healthier in the long run. They thin out the older, sick trees and give newer, stronger growth a chance.

Up close and personal with the Hydro-axe. Photo courtesy Corey Corbett.

For many years it was the policy of land managers to prevent forest fires in order to preserve property and public safety. However they are now learning that when nature can’t do it’s own natural thinning, fuel woods accumulate, disease starts to take over and we end up with an unhealthy forest just waiting for the right time to become an inferno. The Hayman Fire is an example of what happens when there is too much fuel laying around. The fire burns too hot for anything to survive and 1000’s of acres are lost with millions of dollars in property damage. Some believe that a prescribed burn that had happened a couple years before was one of the main contributing factors to Hayman stopping where it did. Once it reached the area that had been thinned, it ran out of fuel to keep going and became easier to get under control.

A section of forest after the Hayman Fire. July 2002. PC: Steve York.

The mulching machines are a much slower, although more selective method of doing the same job. The operators can pick and choose which trees should be removed and there is little chance of the process getting out of hand. The aftermath can look like a war zone however. If you’ve ever ridden a trail that has recently been cleared by a Hydro-axe, you’d know it. There are chunks of debris everywhere and much more daylight than we are used to seeing in Rampart! Use caution when riding in these areas as some of the debris can throw a bike in unexpected directions if hit at the wrong angle. Eventually all the debris will decompose and provide mulch that will help sustain the growth that remains.

View of Hayman smoke plume from Castle Rock. PC: Steve York.

Steve York
Corey Corbett
Leah Hendricks


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