On a crumbling cliff near Denali National Park, a crew of nine men and one woman chips away at a geologic hazard that hangs above motorists passing 100 feet below on the Parks Highway.
Rappelling with heavy-duty ropes, they wear hardhats and climbing harnesses as they knock down loose rocks, picking at the surface with aluminum pry bars about 8 feet long.
They got into this work because they are mountaineers, rock climbers, veterans of the military and people who love extreme sports. Most are in their 20s, but a few are in their 30s and 40s.
More than a few have been to the summit of Denali multiple times, and this job allows them to make a good living by combining climbing with hard labor. They work a 12-hour night shift to reduce traffic disruptions in the busy Denali Park area.
When the weather turns sour with rain and wind, it's as much a test of endurance as any expedition on a mountain. Rain leads to more falling rocks.
"The rock is so weak that when there's heavy rains, it washes out all the little particles from underneath the bigger material and you start getting rockfall," said Mikel Saunders, who is overseeing the job for Advanced Blasting Services of Wasilla.
Wielding a scaling pole for 12 hours and knocking down thousands of rocks is not for the faint of heart. As one of the men said, "It's like doing a thousand pushups a night."
On these cliffs above the highway, the rock scalers find no shortage of material to knock down. The rock faces look solid enough to people traveling at highway speeds, but close inspection gained by rappelling down the cliffs shows that is not the case.
:quality(70)/s3.amazonaws.com/arc-wordpress-client-uploads/adn/wp-content/uploads/2016/06/24144633/Rock-Scalers.jpg)
As the scalers stab their poles against the canyon walls in a steady rhythm, looking for all of the weak spots, small and large pieces of gravel tumble down in a constant stream, sounding like a hailstorm on a sheet-metal roof.
But it's not just sand, dust and gravel cascading down. Every now and then a boulder of a few hundred pounds lets go, bouncing like a basketball, big chunks breaking off with each hit. Steel shipping containers are lined up next to the shoulder of the road as a barrier to keep the rocks from reaching the highway.
When a big rock hits bottom, the container rattles like a garbage can struck with a sledgehammer.
I went Thursday night to the Denali area to get a look at the aerial road job, made necessary by the way that water, ice and gravity wreak havoc on canyon walls that are not quite rock solid.
The road project general contractor is QAP, while the rock wall assignment falls to subcontractor Advanced Blasting Services. At the end of the summer, when the traffic slows, the most hazardous sections will be blasted to improve highway safety.
Eleven spots along the road are to be cleared of loose rock by hand this summer, requiring the climbers to spend about 4,000 hours hanging out, surely the most unusual climbing expedition in the vicinity of Denali.
From 7 to 11 p.m., traffic is halted for a few minutes at a time. All the rock scalers have radios. When the traffic moves, they stop chipping, balanced on their ropes and standing by, waiting for the all-clear signal.
There are flaggers about a half-mile apart on the road and two foremen who monitor the rock scalers and serve as lookouts down below.
From 11 p.m. to 6 a.m., traffic is halted for 45 minutes at a time, allowing the crews to work without constant interruptions. Extra lights are not really needed on the clearest days until well after midnight, but the beams from mobile light plants illuminate the hillside when the clouds settle in.
From the looks of these walls, the loose material should have been removed years ago. It wasn't until last summer, in connection with a major road paving project, that this became a priority.
Running road paving equipment beneath the cliffs along a 3.5-mile section would create vibrations and could trigger dangerous rock slides. To lessen that risk, the rocks are being removed this summer in the first phase of a $13 million project.
Falling rocks are hardly a new problem in this narrow opening where the Alaska Railroad, the Parks Highway and the Nenana River cross the northern edge of the Alaska Range. From the entrance to Denali National Park north to Healy, the river flows about 10 miles "in a remarkable two-story canyon through a high ridge," in the words of a 1958 geological study.
Both the railroad on the west side of the canyon and the road on the east side of the canyon have been hit over the years with repeated landslides from unstable slopes. For the highway, most of the falling rock lands in the ditch to the east of the road that has to be regularly cleaned.
A 2008 report said that about 300,000 cubic yards of rock had been removed from the roadside in this section since the highway opened in 1971. "Steep slopes with active natural slides made this section of the road the most difficult and expensive to construct," it said. "Landslides of talus and cobble-sized rock continuously pour onto the roadway, and block sides, including single slabs up to 1,000 tons, have battered and blocked the road as well."
The members of the scaling crew start their shift by carrying their gear to the top of the cliff before performing safety checks on one another. They work their way down from the top, with caution.
When one scaler loosens a really big rock, they all take note, as if they are in competition with one another. They don't push as hard as they might on the poles, however.
They only want to get the rocks that are loose and in danger of falling, whether from earthquake, rainstorm or paving project.
Saunders said the scalers pay the most attention to the rocks at the top, as those can do the most damage. A 1-pound rock falling 75 feet can be fatal.
"Everything above the man has to be safe, so you have to pay close attention to get that material out," he said. "The farther down the slope they work, the more dangerous the brow of the slope is."
The scalers try to stay at about the same height as they work their way down the cliff because rocks can bounce in unexpected directions. They often take one break during the shift, which requires that they climb back to the top, but spend the rest of the 12-hour shift on the ropes, sculpting the canyon wall.
Columnist Dermot Cole can be reached at dermot@alaskadispatch.com. The views expressed here are the writer's own and are not necessarily endorsed by Alaska Dispatch News, which welcomes a broad range of viewpoints. To submit a piece for consideration, email commentary(at)alaskadispatch.com.