In the summer of 1925, a survey team from the Bureau of Public Roads climbed onto a section of a mountain called the Garden Wall in what had recently become Glacier National Park and looked at a problem that had confounded every road engineer who had examined it before them. The Garden Wall is not a hillside, not a steep slope, but a rock fin, a thin blade-like stone column, formed where two glaciers carved the mountain itself from opposite sides simultaneously over ten thousand years, leaving behind a wall so narrow at its crest that you can stand on top of it and see both sides of the Continental Divide at once. On the eastern face, the wall drops roughly two thousand feet to a lake called St. Mary.
On the western face, it drops to the McDonald Creek valley. The angle of both faces is vertical in many places. The plan called for a road to cross this wall, not over it, but through it, carved into its face. A rock shelf was to be cut halfway up its height, wide enough for two cars to pass, clinging to the cliff for twelve miles at elevations between four thousand and sixty-six hundred feet, passing through sections where the mountain above the road rises another thousand feet of unstable rock, and where the emptiness below drops away so steeply that a man falling from the outer edge would not touch the slope before reaching the bottom.
The engineers who surveyed the line understood the problem. Their surveys allowed them to determine direction and grade, and to tell the construction crews what height and width were required. But what the surveys did not tell them was where the rock would cooperate and where it would not. The Garden Wall was not uniform.
It was ancient sedimentary rock, Precambrian limestone and argillite, accumulated over a billion years, then pushed upward by the Lewis Overthrust, one of the largest geological events in North American history, which moved an entire plate of ancient seafloor more than eighty kilometers eastward over younger rock beneath it. The result was a mountain range made of rock far older than the terrain it was built upon, fractured in patterns no surface survey could fully predict, and subject to conditions no construction crew working in a desert canyon or a river valley had ever faced. Snow. The Garden Wall receives more than 250 centimeters of snow annually.
The construction season at this elevation and latitude was five months at best, from late June when the snowpack melted enough to reach the site until mid-October when it closed again. Some years it was four months. Some years it was less. The crews did not work through winter.
They could not. The avalanche danger above five thousand feet in the northern Rockies in winter is not a risk to be managed; it is a condition that ends human existence on a mountainside. The crews worked for five months, descended before the snow closed the routes to the mountain, and returned the following summer to find the winter’s effects on what they had built. The effect of winter on their work was the problem they solved every spring before they could build anything new.
To understand why anyone would attempt to cut a road across the Garden Wall, you have to understand what the national park meant in 1924 to the people who ran the railroads. Glacier National Park was established in 1910. The Great Northern Railway had been running tourist trains to the park’s west entrance since 1892, when James Hill’s line reached the Flathead Valley. Hill understood something about mountains that the automobile age would confirm.
If you could show people the interior of a mountain range, they would pay money to see it. The problem was that Glacier’s interior was not accessible. The park’s most spectacular regions, the spine of the Continental Divide, the glaciers, the passes, and the peaks from which the park took its name, lay behind the Garden Wall, reachable only on horseback over trails that took many days and required guides, horses, and camping equipment, limiting the experience to visitors with abundant time and money. Automobiles were changing what Americans expected from national parks.
By the early 1920s, the number of cars in the United States had risen from a few thousand to nearly ten million. Those who could not afford a week on horseback could spend a weekend in a car. Parks with roads attracted visitors; parks without roads were silent. The National Park Service, established in 1916, understood this calculation.
Its first director, Stephen Mather, was a businessman who had made a fortune in borax mining before taking the federal post. He believed the parks would be saved by their visitors, and that those visitors would come by road. The Going-to-the-Sun Road was his project as much as anyone’s. A road designed to cross the Continental Divide at Logan Pass, connecting the west entrance at West Glacier to the east entrance at St.
Mary, allowing a drive from one side of Glacier National Park to the other in a single day. That required carving a rock shelf into the face of the Garden Wall for twelve miles at average elevation. The Bureau of Public Roads surveyed the line in the early 1920s. The survey was done on foot by men who walked the cliff face carrying compasses and altimeters, recording bearings while standing on trailless rock.
When construction began in earnest in 1925, the crews had only a line on paper, nothing else on the mountain. The men who worked on the Garden Wall in the summer of 1925 were drawn from the skilled labor force of the northern Rockies, which in that decade meant a specific set of communities. There were workers from the agricultural towns of the Flathead Valley, who had spent their first winters on their homesteads after the land sessions of 1910, and found that farming at altitude with a short season did not meet their needs. There were workers from the mining camps of Butte and Anaconda, men skilled in rock work and handling powder, unbothered by tight spaces or the sound of blasts.
There were also workers from the Blackfeet tribe, whose reservation bordered the park’s eastern edge, and whose ancestors had used the passes through this range for centuries before the park was declared and before the road was even conceived. And there were Italian stonemasons. The Bureau of Public Roads brought in skilled stonemasons for the masonry work on the project, retaining walls, drainage channels, guard barriers, and structures supporting the road base on the cliff face, preventing the collapse of the outer edge under load. Many of these men came from communities in Montana, Colorado, and Wyoming, where Italian immigrant workers had been doing stonework since the railroad era.
They were the second generation of that immigration. Their fathers had handled dynamite on mountain railroads. They themselves carved and set stone on mountain roads. The difference was in the precision required.
A retaining wall carrying passenger cars had to meet standards a railroad embankment did not. It had to look right and be sound. Wages on the Garden Wall varied by skill and task. Laborers earned $3.
50 a day in the mid-1920s. Skilled drilling crews earned between $4. 50 and $5. Powder men earned slightly more for the specialized knowledge required.
The Italian stonemasons, brought in under contract rather than as day labor, negotiated piece rates for specific structures. In today’s value, $3. 50 in 1925 is roughly $62. For a ten-hour workday on a rock cliff at 5,500 feet in the northern Rockies, carrying tools on trails the road had not yet reached, under a system that closed the mountain in October regardless of progress made, the wage was $62.
There was no overtime, no hazard pay, no formal accident insurance. The Bureau of Public Roads kept records of project injuries and deaths with the same terse directness it used to account for material costs. The records noted: “injured worker, date, cause. deceased worker, date, cause.
” Names appear only once. The specific physical problem of the Garden Wall section must be understood before how it was solved makes sense, because the solution only makes sense in light of the reality of the work they were doing. The average grade of the wall where the road crosses it, between the Loop and Logan Pass, is between sixty and eighty degrees on its western face. A sixty-degree slope is steep enough that a person without experience negotiating trails could not walk it without using their hands.
An eighty-degree slope is practically a cliff. The road base had to be cut into this wall at constant elevation, meaning that in the steepest sections, the men were not excavating a slope; they were cutting a horizontal shelf into an almost vertical face. To do that, they had to reach the wall. There was no trail above the road line because the road itself was what was being built.
Before any blasting on the main road base, crews had to cut access trails up the slope to the working height. These access trails were construction achievements in themselves, narrow switchbacks hacked by hand through talus and scattered rock. The slope was so steep that equipment and supplies were carried on muleback or by hand because wheeled vehicles could not negotiate it. Everything that reached the working face of the Garden Wall arrived on the back of a man or a mule: steel drill bits and wooden handles, powder cans, water, food, timber for scaffolding, rope.
All workers climbed the access trails to the site in the morning. Then they returned in the evening because there were no camps on the Garden Wall. The main camp was at a site called the Loop, a large sharp switchback on the west side road, where the elevation was lower and the ground level enough to pitch tents and set up cooking areas. From the Loop to the highest work sites on the Garden Wall, the round trip distance was four to six miles, with an elevation difference of fifteen hundred to two thousand feet.
The men covered this distance twice a day, before and after their shift. This distance was not part of the shift; it was simply a precondition for access. At the working face, the operation involved surveying the line, drilling holes, blasting, mucking out debris, then moving the line forward. Drilling was done by two-man teams.
The first man pressed a drill steel against the rock surface and rotated it between blows. The second man struck the drill head with a four-pound hammer at a steady rhythm, two to three blows per second. With each blow, the hole advanced a fraction of an inch. In granite, progress was slow.
The rock on the Garden Wall is primarily argillite, a metamorphic stone harder than sandstone but less resistant than pure granite. An experienced team could advance a drill hole eight to ten inches per hour. A standard blast round on the Garden Wall required a pattern of holes drilled at specific depths and angles. Usually six to ten holes per round, depending on the width of rock to be removed.
The angle of each hole determined the direction in which the material would be ejected by the blast. A properly drilled round on a vertical face would push the shattered rock outward and downward, away from the mountain into the void. A poorly drilled round would break the rock unpredictably, potentially undermining natural ledges above the blast area or leaving irregular blocks of broken stone that would fall on the crew during the mucking phase. The powder man loaded the holes in sequence and fired the charge.
After the dust settled, the mucking crew went to work, breaking up the remaining fragments with heavy hammers, then collecting the rubble into wheelbarrows or canvas bags and hauling it to the outer edge of the road base under construction, where it was dumped over the cliff. Each blast advanced the road base between two and four feet. To cut twelve miles of rock shelf into the Garden Wall, they repeated this process thousands of times over seven construction seasons. The specific problem that caused the most dangerous work on the entire Going-to-the-Sun Road was not the Garden Wall itself, but a section called the Weeping Wall.
The Weeping Wall is a rock cliff on the upper west approach to Logan Pass, where groundwater seeps through the rock and emerges continuously from the cliff year-round. Even in winter, when the exposed surface is frozen and the seepage behind it continues, working its way through the argillite, the water passes through cracks where accumulated snow and summer rain filter through the mountain and emerge at road level. In summer, water runs down the wall. In spring, the road is ice.
The road passes beneath a rock overhang in this section, which was blasted to create a clearance of twelve feet above the pavement. The blast that created this overhang required drilling into a wet face. The presence of water in a drill hole affects how the charge is handled. Drilling wet rock produces a mixture of fine stone dust and water that accumulates in the hole with the drill steel, and must be constantly removed to allow the drill to advance.
The drilling crews at the Weeping Wall wrapped cloth around their hammer hands to absorb the spray from the seeping face. They worked in wet clothing in an area where the temperature rarely exceeded fifty degrees Fahrenheit, even in July, because the overhang blocked direct sunlight and the wall threw cold groundwater onto anyone standing beneath it. Below the Weeping Wall, the slope drops at about forty degrees for several hundred feet before falling away into a vertical cliff. A man who slipped from the working face at the Weeping Wall did not stop until the slope ended.
Bureau of Public Roads records show that work on the Weeping Wall section took two full construction seasons. One season to establish the road base beneath the overhang, and another to complete the blasting of the overhang and build the retaining structure that anchors the upper edge of the road against the seeping face. Two full years of wet drilling and bitter cold. There are no names on any sign at the site today.
In summer, visitors on the Going-to-the-Sun Road stop at the pullout below the Weeping Wall, walk on foot to the overlook, feel the spray from the cliff on their faces, and take photographs. The work that allows them to stand there is invisible from where they stand. The rope work on the Garden Wall followed the same logic as all other cliff construction projects of that era. The most experienced men went over the edge.
In the steepest parts of the Garden Wall, where the angle exceeded a man’s ability to stand without assistance, drilling crews worked from rope scaffolding lowered from above or from wooden platforms anchored from the road base under construction. The wooden platform was assembled from materials brought in on muleback over the access trails, fitted together by hand without power tools, and secured to the rock face with iron rods driven into holes drilled by hand. A platform section on the Garden Wall might be eight feet wide and six feet deep, suspended over a void hundreds of feet deep, supported entirely by iron rods driven into the face of a damp cliff by a man hanging from a rope. The man who drilled the anchor holes was not a carpenter or an engineer; he was a rock worker who had spent enough time in the mountains to understand where a driven iron rod would hold in the argillite and where it would not.
This knowledge was recorded nowhere; it was in his hands and eyes from years spent on this rock. He drove the anchors, the carpenter built the platform, and the drilling crew worked on it, and the logic of this arrangement was that if an anchor failed, the man who drove it would not be on the platform when it fell, but hanging from a rope beside it drilling the next hole. Picture the scene with the precision it requires. You are sitting on a wooden plank suspended by two ropes over a two-thousand-foot void.
Your back is against argillite cold even in July. The noon light reflects off the valley below you in a mesmerizing way, though it changes nothing. The men who operate your climbing rope stand forty feet above you on the road under construction. You communicate with them by rope tugs.
One pull, lower me. Two pulls, stop. Three pulls, haul me up immediately. You hold a steel drill in your left hand, its bit against the rock.
Your partner, on his own rope, six feet to your right, swings the hammer. The wall is damp from the morning mist that fills the valley below Logan Pass on most July mornings. The drill slips if your angle is not perfect. You correct it.
The hammer swings. You feel the shock travel through your forearm to your shoulder. You rotate the drill slightly. The hammer swings again.
After two hours of this, you will find yourself with an eight-inch hole and a bruise running the length of your left forearm from the vibration, which will last two weeks. Then you will come off the wall and eat cold beans from a metal plate, and return to the rope the next morning. Blackfeet workers appear in the Garden Wall section in the correspondence of the Bureau of Public Roads construction office as local labor. In the payroll records, they appear as laborers without further specification.
The correspondence of field supervisors occasionally notes that some workers showed good knowledge of mountain terrain, which benefited them in locating trails in the upper areas. The wording is administrative and does not explain what is meant. What is meant is that men whose families had crossed the passes of the Continental Divide for generations before the park existed were paid $3. 50 a day to guide Bureau of Public Roads engineers to locations their surveys could not pinpoint accurately from the valley floor.
This knowledge was not costly; it was included in the daily wage. The Triple Arches are a section of stone retaining wall on the west approach to Logan Pass, visible from the road where the road crosses a watercourse descending from the upper Garden Wall. Three stone arches, built without mortar, fitted from argillite and limestone quarried from the surrounding terrain, carry the road over a stream that in spring carries enough water to undermine any poured concrete structure that had not been built with sufficient consideration for the movement of material beneath it. The arches are built dry, without mortar.
Each stone was selected from the valley by an experienced mason who understood the weight it would bear and the geometry of the arch of which it formed a part. The keystone of each arch is fitted so precisely that the pressure of the stones on either side holds it in place. Removing the keystone would collapse the arch. Leave it in place, and the arch becomes stronger under load because the pressure compresses the joints and forces the stones to bind more tightly.
The mason who built the Triple Arches worked from knowledge, not drawings. The drawings existed; the Bureau of Public Roads provided specifications for all masonry structures on the project, but the drawings showed only dimensions and materials. They did not show which stone to choose from the surrounding terrain. They did not show how to read argillite for fracture lines that might cause a stone to split under load a decade later, while appearing sound when installed.
They did not show how to dress the bearing surfaces of each stone so that the contact between stones was flat enough to transfer load without creating a stress point that would crack in the freeze-thaw cycle. This knowledge was acquired by the mason himself, from wherever he learned it, whether in an Italian mountain village or on a Colorado railroad or both. It stayed with him. He applied it to a stone wall in Glacier National Park in 1928, and the wall still stands today.
The freeze-thaw cycle at five thousand feet in northern Montana is relentless. Water seeps into rock cracks in autumn, then freezes in November, expanding, pushing the rocks slightly apart. It melts in April, contracting. This repeats every winter.
Nearly a hundred years have passed since the Triple Arches were built. The arches still stand, and the road still crosses them. Every spring, when the snowplow makes its first pass on the Going-to-the-Sun Road to open it for the season, it crosses the Triple Arches built by a man whose name appears on no memorial plaque within a hundred miles of where he built them. The Going-to-the-Sun Road was completed in 1932 and officially opened on July 15, 1933.
The ceremony was attended by officials from the National Park Service, the Bureau of Public Roads, and the Great Northern Railway. Stephen Mather, the visionary who had driven the project from its beginning, died in 1930, two years before the road was completed. He did not see it open. The men who built the road were not present at the opening ceremony; they had moved on to subsequent projects.
Official records put the total construction cost at about $2. 5 million, roughly $45 million in today’s dollars. The records include materials used, contracts, and completion dates. The names of the day laborers appear in payroll records, preserved and available to researchers.
But what these records do not show is the nature of each worker’s job; they only record name, daily wage, and number of days worked. These records do not distinguish between the man who pushed a wheelbarrow on level ground and the man who drilled anchor holes on a rope over a two-thousand-foot void. The road was designated a National Historic Landmark in 1983, in recognition of the engineering achievement and aesthetic integration with the surrounding landscape. The official document describes the road as an outstanding example of harmony between built infrastructure and natural terrain, and this is an accurate description.
The road blends into the landscape as if it were part of it, its curves following the natural lines of the mountain, its stone walls matching the color and texture of the surrounding rock. This is no accident; it is the result of men who chose every stone from the mountain they built in, and placed it so precisely that the joints between stones disappear into the geological formation. The harmony between road and mountain is the product of their labor. The construction of the Going-to-the-Sun Road caused the deaths of workers, with Bureau of Public Roads records documenting eleven deaths during the project period.
The causes listed include rockfalls, falls from heights, and equipment accidents. Eleven is the officially recorded number. This number does not include the men who left the project with injuries that eventually killed them, or the men who inhaled rock dust for six construction seasons and died of lung disease in the 1940s in some town in the Flathead Valley, with no recorded connection to the road they had worked on twenty years earlier. By 1925, silicosis from rock drilling was understood in a way it had not been in 1879.
The medical knowledge existed, but its industrial application did not. It was known that wet drilling, passing water over the drill head to suppress fine rock dust, reduced silica exposure. This practice was not standard on Garden Wall construction, because water had to be carried to the work site, and the drilling crews were already carrying everything they needed along the two-thousand-foot access trail. Adding a water supply to this logistics chain required a decision by someone with authority.
And the men whose lungs would bear the consequences of that decision not being made were not the ones with the authority. This is the sentence that stays with me whenever I read the Bureau of Public Roads field reports on the Garden Wall construction seasons. The decision about wet drilling was a matter of logistics and cost, and it was decided on that basis. The argillite dust they drilled entered their lungs because no one with the power to make that calculation was aware of the result.
Today, the Going-to-the-Sun Road is open from mid-June to mid-October, the same season that constrained its construction. The road receives about two million visitors annually. It is managed by the National Park Service as a historic road, meaning modifications must preserve the character of the original construction. When sections of the retaining wall collapse, they are restored with the same material and the same original technique: dry-laid argillite fitted by eye without mortar.
There are still masons doing this work today, who learned it from studying the original walls and from working with those who in turn worked with those who mastered the craft. The chain of knowledge is still intact. This site has passed through many hands since the men who built the Triple Arches set their last stone and walked back down the access trail in 1928. Those trails have disappeared; they were temporary routes cut during the construction season, then abandoned when the completed road provided access from below.
Their only remaining trace is in construction photographs, where they appear as thin scratches on the slope above the road base, merging with the talus a few hundred feet above the camera frame. The road is the record. There is a section between the Weeping Wall and Logan Pass where the road base was cut into the Garden Wall face at its steepest angles. The outer edge of the pavement ends at a native rock edge capped with blocks of argillite, placed by construction workers in the late 1920s.
On the far side of that edge, the wall drops to the valley. If you stop at the parking lot just below Logan Pass, walk to the edge and look down, you will see the road line below you on the sharp switchback, and below it the Garden Wall slope, and below it the valley floor nearly two thousand feet down. The scale of the scene is not immediately apparent; it takes a moment to grasp what you are seeing. What you are seeing is a shelf in the face of a cliff, a shelf twelve feet wide and twelve miles long, carved by hand into a mountain that took 1.
7 billion years to become what it was before the men with the drills arrived. They borrowed their working space from the rock, took what it offered, shaped it with steel and powder, and with their understanding of how stone breaks and where it holds. Then they walked the access trail for the last time in October, and winter came and covered what they had built. And when the snowplow climbed up in June, the road was still there.
This scene has been reenacted every June since 1933. The drill marks from the Garden Wall construction are still visible in some sections of the cut face. Regular circles carved into the argillite where star drills entered ninety years ago. There are no signs or markers.
Most visitors pass them at fifteen miles an hour enjoying the view without noticing, but they are there. And if you slow down and look at the cut face of the rock as you pass through the steepest part of the Garden Wall, you will see them. Small circles in the stone, precisely placed, the diameter of a steel drill bit driven by a man tied to a rope over a valley he was told was a national park and would be cared for forever. He drilled the hole.
He set the explosive. He moved away, and the mountain fell, and the road was cut, and his name was not recorded anywhere I have been able to find, but the hole is in the rock and the road is still there.
