Fire On The Mountain

The sun wasn't yet up and I was standing in a grassy field, next to a rickety row of white tents and plastic banquet tables stacked with sugary baked goods and cold Egg McMuffins. About 60 men (and a handful of women) in puffy jackets, cargo pants and bright yellow, flame-resistant shirts milled about, drinking coffee and trying to stay warm. Parked around us were about 20 trucks, four-wheel drive vehicles and fire engines, one of which had a giant map tacked to it.

Yesterday, I was at my very first prescribed burn and it was fantastic. I'll admit - the morning started off a little slow. "Be here for the 7am briefing," they said. It started at 8am and lasted 10 minutes. The burn didn't start until 10am - which left almost two hours to kill in the 38 degree, breezy morning air before seeing any action. But it was totally worth the wait.

A prescribed burn is a deliberate use of fire by the US Forest Service or other land management agencies (in this case, Boulder County) to improve forest health and reduce the amount of fuel that can otherwise contribute to an extreme wildfire event. 

This particular burn took place in one of Boulder County's Open Spaces - an area known as Heil Valley Ranch. It's north of Boulder, nestled into one of the many canyons along the Front Range as you drive along Highway 36. The ranch belonged to a family at one point but, as the owners have gotten older, they've sold off chunks of the property to the county, which now owns over 5000 acres. It's a gorgeous spot - the foothills are covered in grasses and ponderosa pines and if you look down the valley to the south, you can see Bear Peak rising above the Flatiron Mountains. 

A little bit of background here: for about a century, there was a general belief in the US that fires were a really bad idea. That led to a policy of complete fire suppression - basically, don't let anything burn and if it does catch fire, put it out ASAP. It was something of a misguided notion - we've since come to realize that fire is necessary to this landscape, just as important as rain. Fire's necessary to keep forests healthy, both for the trees and for the other plants and animals that live in this ecosystem and, in the end, regular smaller fires - coming every 20 years or so - can prevent huge, catastrophic fires from roaring through.

Unfortunately, we didn't really get that so, during that century of fire suppression, A LOT of trees grew. A lot a lot. On Heil Valley Ranch, there were as many as 3000 trees per acre. The healthy number is somewhere closer to 70 or 80 per acre. So you've got unhealthy forests that are absolutely choked with trees - forests that are more prone to disease, where other native species are crowded out and where, if a fire does start, it can quickly climb up into the tops of the trees - what's known as a crown fire - and get out of control. 

So, before the county could even think about doing a prescribed burn here, they had to get in there and start thinning out the trees. Cutting them down, spacing them out, removing dead and dying trees - trying to restore some semblance of what these forests would look like naturally. This is an incredibly labor-intensive process. Forest management teams have to get into the forest where there are no roads, cut down trees and haul that stuff out to places where it can be burned - much of this is done by hand. Ultimately, though, if it's done right, a fire here - whether prescribed or natural - will move more slowly, crawling along the ground and consuming grasses and seedlings and leaving mature, healthy trees behind.

Now - back to the burn. The county has prepped about 150 acres that they were hoping to burn over a three to five day period. They may not get it all done this year - doing a successful prescribed burn relies heavily on a wide variety of conditions - temperature, humidity, how much moisture is in the vegetation, wind, air quality. Everything has to be monitored very carefully and if one of these conditions changes, that can mean shutting the whole operation down, or only doing parts of it, leaving the rest for another year.

Yesterday morning was really cold and the wind was already kicking up a bit, making the burn bosses question whether the burn could even happen. But after running a test fire, conditions seemed favorable and they continued. Firefighters, using what are called drip torches (they contain a mix of diesel and gasoline - a less flammable, flammable mixture), incrementally lit grasses and scrub on fire. 

That fire spread and, if all looked like it was going ok, they took a few steps back and lit up some more fuel. The wind was at their backs, so the flames and smoke moved away from them toward the poor firefighters on the other side of the fire, who (aside from trying to avoid smoke inhalation) were watching closely to make sure no fire escaped or got out of control.

From where we media types were standing, we could only see smoke at first - big black plumes rising into the morning sky. Every now and then, you'd catch a glimpse of a bright orange, high-reaching flame. As the fire got closer, it was mesmerizing. Flames rapidly consumed grasses, stumps and and low-lying shrubs. They ran up the sides of healthy trees, burning off lower, dead branches and turning pine needles into spots of fluorescent orange before they curled into ash. What's cool is that these older trees are meant to withstand fire - their thick bark protects them, flaking off in places - and the fire would really only lick their outer edges before moving on to more combustible fuels.

And man, was it hot. From fifteen feet off, you could feel the heat - which was nice, given how cold I'd been all morning. From ten feet, I was wishing I didn't have so many layers on. At five feet, I could feel the skin on my face tightening and the moisture evaporating from my lips. I can only imagine how toasty it was for the people actually walking around in it, wearing heavy protective layers.

All in all, a pretty neat way to spend a morning and some good insight into how involved forest management is and how careful these guys are during this burn process. They'll be up there for several more days, burning more acreage and then making sure that everything is out once they've finished.