Work on a project that began in 2014 to thin unhealthy tree stands on Bald Mountain is scheduled to resume on July 7 and extend to mid- to late-September.
The project has so far focused on the Frenchman’s area and Flying Squirrel, but this summer will thin additional stands in Central Park—near the top of Baldy between Upper River Run and College run—and on the skier’s left side of Limelight, according to Sawtooth National Forest North Zone Forester Nelson Mills.
The project has been a precursor to the larger Bald Mountain Stewardship Project, which was approved by Ketchum District Ranger Kurt Nelson last week to address forest health and hazardous fuels reduction on Baldy and adjacent areas over an expected 10-year timeframe. That project will remove dead and diseased trees and plant seedlings on a total of 920 acres of national forest and BLM land at the Sun Valley ski area.
The current project encompasses 182 acres. Since summer 2014, crews have worked on 25- to 50-acre sections each year. It provides an added benefit to skiers by creating more glade skiing through spaced trees. The project has cost about $100,000 to $150,000 each year, split between the Ranger District and Sun Valley Co., according to the Forest Service.
Mills said this summer’s work will be done by tethered machinery designed for steep slopes.
“It’s some pretty high-tech stuff,” he said. “It’s really light on the land.”
Mills said crews will remove dead “hazard” trees along the ski runs, remove dwarf mistletoe-infected trees and thin insect-infested stands. He said the thinning is intended to reduce Douglas fir bark beetle infestation by increasing the distance the beetles have to travel between trees and by leaving the healthiest, most resistant trees.
In May, 3,000 Ponderosa pine seedlings were planted in the Frenchmen’s area in places thinned in 2016, 2018 and 2019. Mills said lodgepole pine will also be planted there.
“Increasing species diversity in a stand will reduce the potential for one type of bark beetle to reach outbreak levels,” he said. “It also reduces dwarf mistletoe spread. Bark beetles and dwarf mistletoe species target specific tree species.”
Mills said that in addition to the Douglas fir bark beetle, other destructive insects on Baldy include the Douglas fir tussock moth and Western spruce budworm, which attacks Douglas fir, subalpine fir and Engelmann spruce.
Mills said Ponderosa pine is native to the area, but exists naturally in only a few places in the Wood River Valley, particularly in the Baker Creek drainage. He said that early in the 20th century, the Forest Service planted Ponderosa seedlings in Oregon Gulch, Adams Gulch, Greenhorn Gulch and the Deer Creek drainage, but most of those trees were burned in the Beaver Creek Fire in 2013.
Zach Poff, the Ranger District’s recreation and winter sports programs manager, said he expects some of the seedlings planted in gladed areas to be cut by skiers once they poke above the snowpack, but that shouldn’t have much effect on the regrowth of the forest.
“I do think there’s some mortality from skiers, but some of the thickest regeneration we’re getting is along the edges of ski runs and in the middle of ski runs,” Poff said.
A finding of no significant environmental impact by an environmental assessment released by the Forest Service last week cleared the way for Nelson’s decision to approve the Bald Mountain Stewardship Project. Mills said that following a legally required 45-day public objection period, crews will go up on Baldy in August to mark areas to be thinned. He said the actual cutting will not begin under that project until next summer.