FAIRBANKS -- A 647-mile section of the Alaska-Canada border runs on a straight line from Mount St. Elias to the Beaufort Sea, following the 141st meridian.
More than a century ago, crews struggled to turn the simplicity of an unbending line into marks on mountaintops and valley floors. They planted monuments in concrete and cleared a 20-foot swath across hundreds of miles of forests and hills. The work took seven years.
"The line now constitutes a very prominent and noticeable feature of the landscape," a 1918 report concluded, "and one that will remain so for many years owing to the slow growth of timber in those northern latitudes."
The task of defining the border falls to the International Boundary Commission, an organization created by treaty with Canada that includes two commissioners, one from each nation. Under the direction of the commission, the path between Alaska and the Yukon has to be cleared every 25 years or so, a job that has typically been spread out over five or six summers.
The low-key commission "represents a true sharing of resources, intellect and goodwill between the two sovereign nations with little fanfare, less hoopla and no jingoism," according to a recent history written by the Canadian commissioner, an adviser to the commissioner, and the former U.S. commissioner.
Three crews, one of which is Canadian, are wielding chain saws and brush cutters this summer along the 141st, hoping to clear about 130 miles of the line.
From the air or from mountaintops, the unbending course of the Alaska-Yukon border does not convey any sense that it exists to restrict passage from east to west. It is a linear north-south connection.
A few years back, Swiss photographer and climber Ruedi Homberger, who has explored the Wrangell Mountains for more than 20 years, flew along the line with his friends Paul Claus and Chris Larsen to see "the next horizon."
"We flew from Paul's lodge in the Chitina Valley to the White River. Soon the line was visible. We continued to Eagle -- the last fuel stop for a long distance," he said. "We camped on the Porcupine River on a sandbar, near the old trading post of Rampart, and continued through the mountains."
"With so much untouched wilderness, my thinking was, 'Why would the two countries clear cut a several-feet-wide path?' "
Defining the border
Unlike the international boundary of the southwestern U.S., the source of bitter conflicts in recent years over keeping people from getting in, if you go beyond the chokepoints that are the highway crossings of the Alaska-Yukon line, this border is among the most placid and little-noticed dividing lines in the world. There's no talk of building fences or patrolling with guard dogs. It might be different if most border crossings were not made by caribou, moose, bears and other creatures with little regard for sovereignty.
To maintain order on the border, the boundary commission follows a regular schedule to cut trees and brush down to 6 inches off the ground for 10 feet on each side of the invisible line. This cycle on the 141st meridian began in 2010. The last major clearing project took place in 1985.
The two countries declared a century ago that in addition to the 20-foot "vista" they wanted to open to the sky, a strip along the line of about 60 feet on each side would be off-limits to development.
Kyle Hipsley, who began as a temporary employee with the commission in 1973, has served as the acting U.S. commissioner for several years. Hipsley, who reports to the secretary of state, said the U.S. is spending about $700,000 this year on the Alaska border work, with the hope of finishing next summer.
"They've got another 40 to 50 miles next year, and they will turn their attention to the monuments," he said. The two nations split the costs of border upkeep, though their employees and contractors work independently.
The crews working with chain saws and brush cutters are supplied by helicopter, which makes the task easier than a century ago when the teams used handsaws and traveled with packhorses. The maintenance crews are also making minor repairs, painting and photographing the monuments that separate the nations.
Hipsley said this is so that when monuments need to be replaced, new ones can be put back in the right spots. There are 191 boundary monuments along the 141st, spread out every three or four miles. The original goal was that one would be visible from the next one along the line with survey equipment.
If some of the original markers were off by a few dozen -- or a couple of hundred -- feet here and there, which was inevitable given the conditions in which the crews worked and the technology of the time, it doesn't matter because it is the position of the monuments on the ground, not the 141st meridian, that is the de facto boundary by treaty.
"The boundary is where the monuments are, not exactly on the 141st," he said. "They did an excellent job, especially when you consider what they had to deal with."
"Imagine what it would take if someone told you go to out there and mark the 141st," he said.
Minor maintenance is taking place this summer but a more serious repair effort, if needed, will happen after the clearing cycle wraps up. The small monuments are 30 inches high, while the larger ones, of which 11 were installed a century ago, are about 5 feet high.
One that has proven to be particularly vulnerable is Monument No. 1, located at the edge of the Beaufort Sea.
"Monument 1 has washed away at least twice that I know of," Hipsley said. "Erosion has taken the original site. We still know where that point is but we put it farther back from the water."
He said Southeast Alaska, which is on a 15-year clearing cycle, is the most difficult section of the entire U.S.-Canada border to maintain because of the mountains, the rain and the growth of vegetation.
"It doesn't get any harder," he said.
"Southeast Alaska is coming up again, probably in the next three or four years," he said. "We've more work to do there than on the 141st."
In the Lower 48, North Dakota and parts of Montana are the easiest parts of the border to maintain because the brush is easy to clear.
"The reason the cycle is quite a bit longer in Alaska is that you don't have the growth of brush that you have, for instance, on the 49th (parallel) between Washington and Canada. That's a fairly damp area and fairly warm. Within four or five years you can hardly tell where the border is."
He said the clearing work remains important both in the Lower 48 and in Alaska because not everyone has access to a GPS and because people traveling across the border need to recognize it. That applies even in areas where there aren't many people, he said.
"It's important that we have a visible boundary. We cut those lines in Alaska where a lot of those monuments are more than two miles apart. So if you are between them, how would you know where the line is? With a clear vista, as soon as you walk into a clear area, there's no doubt you are on the boundary."
To keep the crews on the straight and narrow, they mark the ground every 200 to 300 feet so that the 20-foot cleared patch doesn't deviate much from the map and to prevent getting off course.
There has been no real need to add many more monuments in the Alaska sections, though it is a different story in the busier sections of the country.
"They have a lot more problems down in the Lower 48," he said.
'Straight and good'
In Alaska, the key dispute in the early 20th century about the border was over how to separate U.S. territory from Canada in Southeast Alaska. Thomas Riggs Jr., who served as governor of Alaska after working as chief on the Alaska Boundary Survey, wrote that there was no real disagreement from Mount St. Elias to the north.
The seven-year project was marked with "almost unsurmountable difficulties," said Riggs, a civil engineer who studied at Princeton, but they were the happiest years of his life. He said they began by pinpointing their location on the Yukon River astronomically, determining the time through telegraphic communication by way of Dawson and Valdez.
On the maps, Riggs wrote in National Geographic in 1909, the boundary was easy to follow with the eye, "but the work of putting this line on the ground is still in progress and both American and Canadian surveyors are putting forth their best efforts to establish a boundary which will stand the test of time."
He concluded his account by looking forward 100 years to 2009, imagining a dirigible pilot of the future who would hover between Alaska and Canada and marvel at the work of the old monuments men down below.
The pilot "may look though his improved surveying instruments along the vista from the Arctic to Mount St. Elias and pronounce the line laid out by the old-timers straight and good," Riggs said.