The Pioneer Fire started a year ago this week in the backcountry just north of Idaho City. The blaze would rage on for months, darkening the sky with smoke and eventually charring almost 300 square miles. Although the fire is now a memory, a lingering danger remains: dead trees. Millions burned in the Pioneer Fire and more could catch with a single spark in the Boise Foothills.
As the small propeller plane soars over the rugged terrain between Idaho City and the Sawtooth Mountains, just how expansive 188,000 acres is becomes clear. That’s how much land the Pioneer Fire consumed between its ignition last July and its eventual containment in November. Trees, yurts and even the very ground were consumed by wildfire. Looking at a map of the burn area doesn’t do it justice; only seeing it from the air provides the perspective of mile upon mile of scorched earth.
John Roberts' crackling voice comes through on the plane’s intercom, telling the passengers what they’re looking at.
“And the fire runs for another twenty miles that way,” he says pointing out the plane’s windshield to the northeast. “The hard burn Rock Creek out the left window. That’s Deadwood River there, goes up that way. Clear Creek goes up this way.”
Roberts is the emergency manager for Boise County – the region most impacted by the Pioneer Fire. He was aboard the small plane operated by the nonprofit Ecoflight that flew several people over the burn area to give them the aerial view. From the sky, one of the most striking sights is the endless stands of charred trees; they look like a sea of used matchsticks.
Once the flight lands back at the Boise Airport, Roberts says a recovery operation will get underway in the burn scar. Obviously hundreds of square miles of dead trees won’t be clear cut, but Roberts characterizes some clearing of the area as a needed safety precaution.
“There are folks that don’t like to see salvage operations period after a fire because burnt acres are more sensitive to disturbance,” he says, “but these acres get a lot of use from recreationists and the population base of the Treasure Valley. It’s not safe to be recreating in those forests the way they are right now.”
It’s easier to imagine a tree that looks like a charred twig falling over than one that’s still green and apparently healthy. However, the danger is pronounced in the forests on the Treasure Valley’s doorstep.
“Eighty to ninety percent of the Douglas fir trees have some level of infection of dwarf mistletoe. That’s a pretty high level; there’s not many places where you see it at that level,” says Scott Wagner. He works for the Forest Service as a silviculturist – a great Scrabble word and a fancy term for a forester.
He sets the scene.
“Where we are right now: we’re up in Bogus Basin. We’re on Boise National Forest just north of the ski area here. We’re actually directly adjacent to some of the groomed Nordic trails.”
And these trees that overhang the trail that’s a stone’s throw from where we’re standing – they look weird. They’re thick and bushy at the bottom, but as they rise they thin out. Not the typical taper of a pine tree, but splotchy patches of no branches or clusters of dead growth up around the crowns of the trees. These are tell-tale signs of mistletoe according to Wagner.
“Frequently it kills the top of the tree and then those tops will start to decay,” the silviculturist says. “They can fall out of a tree and become a hazard. It's a parasite on the tree; it survives completely from the tree. It also can weaken the tree and make it susceptible to bark beetles.”
With mistletoe leaching away the Douglas firs’ nutrients from within and bark beetles attacking from the outside, the Boise National Forest isn’t in the best health.
Standing in a clearing and looking around at nearly every tree infected with mistletoe, Wagner says a tree just collapsing on its own is rare.
“But,” he says, “we’ve got a situation in these burn areas and in this ski area where we have thousands and thousands if not millions of dead trees in areas where there are people recreating every day. And you just increase the odds – just by the numbers – you increase the odds of something happening and somebody getting hurt.”
To reduce the threat of injury or fire from the diseased trees, Wagner says the Forest Service plans to remove some of the most seriously infected Douglas firs. After a commercial timber sale slated for some time in 2018 around Bogus Basin, the plan, according to Wagner, calls for “some additional tree felling. And then we will follow all of that up with an understory burn. Then we’re also looking at planting some trees.”
To try and end the cycle of dwarf mistletoe infecting nearly every tree, Wagner says Ponderosa Pine will be planted in the forest. That type of tree is resistant to the mistletoe and does better in the warmer, drier conditions affecting the area as a result of climate change.
Another person who participated in the flight over the Pioneer Fire burn area is Brad Wilson, the general manager of Bogus Basin. As the tiny plane made its way back to Boise, it buzzed the ski area and forest atop the hill. Stands of dead or dying trees were apparent through the clouds. Wilson says he’s on the same page as the Forest Service.
“From the summer perspective, having potential hazard trees around trails is problematic,” Wilson says. “We totally support the initiative to try to remove trees when we can and slow down the progress of the mistletoe and bark beetle.”
The Boise National Forest around Bogus Basin and the Pioneer Fire burn area are both dramatically different from what they once were. Last summer’s huge wildfire transformed miles of woods in hours. The parasitic mistletoe and bark beetles have been slowly at work in the foothills for years. Both areas can recover, says Scott Wagner the silviculturist, but managing the restorations are projects that will span generations.
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