Backpackers and horsepackers who’ve hiked and hoofed it all the way to the remote country south of Yellowstone known as the Thorofare will be in for an unexpected sight this week.
From Thursday through Saturday, helicopters will make up to eight trips a day, transporting lumber and other materials to the banks of the Upper Yellowstone River near Hawks Rest, a 9,777-foot mountain famous for being as far as one can get from a road in the Lower 48 states. At the site, a generator will be running, and engineers and construction workers will deconstruct a 61-year-old, 155-foot eroding bridge and ready the river crossing for a replacement steel structure.
“We will do everything we can to minimize impacts to our visitors, but there is no way to completely avoid temporary impacts to visitors’ opportunity for solitude when helicopter flights are occurring,” Todd Stiles, the Bridger-Teton National Forest’s Blackrock District Ranger, wrote in an email to interested parties this week. “With the Teton Wilderness being nearly 600,000 acres, there will still be ample opportunities for visitors to completely avoid disruption to their wilderness experience.”
The authorization to swap out the Hawk’s Rest bridge was granted in 2017, when the forest opted to replace the structure that predates the 1964 Wilderness Act by four years. The bridge, which is in disrepair, is considered a critical link across a wide, often deep river along the most-used trail in the Teton Wilderness.
When the project was in the planning phases, conservationists knocked the forest for perpetuating a man-made structure that’s incongruent with wilderness ideals.
The Bridger-Teton countered that doing away with the structure would create a safety hazard by forcing wilderness travelers to ford a major, sometimes swollen river. The forest selected a replacement design — a 172-foot steel bridge — after completing a “minimal requirements analysis,” which is necessary to comply with the Wilderness Act. They decided that the single-span structure would have less effect on the Yellowstone River, because it would not require abutments in the riverbed that would alter its flow.
Stiles’ 2017 decision about the bridge replacement called for using hand tools and pack stock whenever possible — and he pledged to make sure of it.
“I am in personal contact with the contractor to ensure that every component of this project that may be feasibly done with traditional tools and pack stock is done that way,” he wrote in the email.
A Bridger-Teton engineer leading the project will stay on site at all times. Construction crews will camp at the Hawks Rest patrol cabin and in the pasture just below. The construction will only cause access issues on days when helicopters are slinging supplies and some trails close.
Although construction starts this week, the large “type one” helicopter needed to fly in the 9,000 to 15,000-pound steel bridge segments isn’t expected to arrive until Aug. 28 — a day that could be changed if wildfire activity pulls the chopper elsewhere. The Bridger-Teton expects to finish replacing the Hawks Rest bridge by mid-October.