Fire investigators have concluded that sparks from a mountain bike pedal striking a rock caused a recent fire in a US National Forest that spans parts of California and Nevada.
A statement posted Wednesday on the Inyo National Forest Facebook page claimed that an investigation determined the cause of the blaze to be a pedal strike.
“The cause of the Rock Creek fire that started on August 5th has been determined. Investigators have concluded that the fire was started from a bicycle pedal strike to a rock. Conclusive evidence was found in the fire origin area that was on the Lower Rock Creek mountain bike trail. A fire ignition from this type of trigger is a testament to how dry the area is right now. All residents and visitors are asked to be extremely careful with anything that may cause a fire while you are out in the forest,” the post read.
Inyo National Forest spans portions of eastern California and western Nevada. Extremely dry summer conditions have increased the risk of forest fire. The Rock Creek fire burned approximately 122 acres before it was suppressed.
Speaking on behalf of the Inyo National Forest, fire prevention technician Kirstie Butler told BikeRadar that, while the exact cause of many forest fires go unresolved, the evidence in this instance was definitive.
“All the holes in the Swiss cheese lined up perfectly,” Butler said.
Investigators traced the source of the Rock Creek fire back to a single rock on a trail surrounded by cheatgrass. Cheatgrass is an invasive species in the western United States that is quick to grow back after fires. It dries out in summer, creating a fuel source for subsequent blazes.
The day the fire started, temperatures were high, winds were moderate and humidity levels were in the single-digits — ideal conditions for wildfires.
Marks on the rock and bits of metal indicated that a spark from a pedal strike ignited the cheatgrass.
"Like striking a flint"
“It really doesn’t take much for cheatgrass to ignite. Anything could start a fire in conditions like this. It would have been like striking a flint,” Butler noted.
According to Butler, while this may seem like an incredibly unlikely chain of events, the US Forest Service has evidence that this has happened before. She notes that sparks from chainsaws and lawn mowers are frequent causes of wildfires. To date, there have been 4,084 wildfires in California, burning a total of 150,498 acres in 2016.
Butler, who is a mountain biker and has frequently ridden the Lower Rock Creek Trail, doesn’t believe the incident will result in trail closures to mountain bikers, nor does she view mountain bikers as more of a fire hazard than any other trail user group.
“This is not about pointing fingers; we know it wasn’t done maliciously. We understand that mountain biking is a popular activity and we’re not trying to say that this is a reason to stop. It’s just something to be aware of,” said Butler.