A red-and-white helicopter that made repeated forays over Bald Mountain Thursday morning signaled the opening salvo in local forest officials' effort to protect the stately old Douglas firs that grace the popular ski mountain.
Weather permitting, the helicopter will fly again today, May 7.
The enemy in this case is an entirely natural one, the Douglas fir bark beetle. Since the Castle Rock Fire roared across the Smoky Mountains west of Ketchum in 2007, many of the Douglas fir trees that survived have been walloped with an explosion of the tiny beetles.
Officials with the Sawtooth National Forest say the outbreaks are a normal response of the beetles in the years after a major event like a wildfire. Trees stressed in the aftermath of the large, 48,500-acre fire are presenting easy pickings for the beetles.
"It allowed the beetle population to explode," said Joe Miczulski, recreation and winter sports specialist for the Ketchum Ranger District.
Recent drought conditions have also stressed local forests of Douglas fir and further robbed them of their natural defenses against beetles.
The forest hired a private contractor from Baker City, Ore., to apply pheromone methylcyclohexenone (MCH) flakes in the Bald Mountain area. The project is expected to wrap up today as long as the weather holds.
The pheromone is naturally produced by the beetles to let other beetles know that there is no more room in a tree, thereby preventing overpopulation in a single tree. By replicating MCH and applying it to trees that have yet to be infested, the Forest Service can trick beetles into staying away from certain areas and keep them hunting elsewhere for trees to infest.
MCH flakes have never been connected with adverse effects on humans, animals or the environment, Miczulski said.
In all, the forest is treating about 2,000 acres on Bald Mountain. They expect to conduct another round of the treatments in late June.
Forest officials fear that the sheer size of the growing beetle outbreak could threaten to overcome even the healthiest Douglas fir trees. Typically, beetles impact small stands of several trees or more. The signs that a tree has been killed by the bark beetle are red needles. At that point, nothing can be done for the tree.
"There is always an endemic population," Miczulski explained. "It's usually small."
The Forest Service doesn't normally engage in large-scale efforts to combat the spread of Douglas fir bark beetles, a natural inhabitant of forests in Idaho and elsewhere across the West. Normally, officials let the outbreaks—which typically run between two to three years, unless drought conditions are especially severe—run their natural course.
But the situation is different on 9,151-foot Bald Mountain, whose storied ski runs and beautiful views are important for the local economy.
"The vista from here in Ketchum is so important," Miczulski said.
Watching the helicopter come in to refuel and fill up on more MCH flakes Thursday morning, he said the pilot is being guided by an onboard GPS unit downloaded with the exact coordinates of infected stands. The pilot drops the MCH flakes on the trees from side-mounted drums.
Forest health protection dollars given by the Forest Service to Idaho and other states are paying for the Baldy project. The Forest Service may elect to conduct more operations over the course of the next four years depending on how the forests respond to the treatments.
Jason Kauffman: firstname.lastname@example.org