- Historic Sites
The Last Map Makers
Another frontier closes as the mapping of America approaches completion
September 1991 | Volume 42, Issue 5
According to Jamie’s instruments, Coyote Butte is 37,797.4 feet away and 30 minutes and 6.5 seconds below horizontal. Later, in the Denver office, others will determine whether these elevations are accurate enough to be retained on the map. They’ve got such good mathematics, they don’t even need to test elevations in the field anymore,” Jamie says. “You give them one fixed elevation and they send it through aerotriangulation and they can get twenty more elevations off that one. It’s pretty expensive to be out here, and so we don’t do this very much.”
The official dream of the main U.S.G.S. office, in Reston, Virginia, is that geographical data for the entire country will eventually be stored digitally. Buying a map will entail specifying not just the quadrangle but also what you want on it: latitude and longitude, contour lines, mineral rights. The computer will then print your tailor-made map while you wait. Many maps will be updated not by field workers but by office workers studying satellite photographs—”photographs so accurate,” Jamie says, “that they have identified the plumbing in a burnt-down house.” Such photographs are also used for spying, and to work with them requires a security clearance. Jamie has applied for a clearance, but the FBI is stumped; she has moved around so much in her life that they can’t find anyone who knows her. They finally had to call her for help.
When a cartographer does go into the field in the future, the control work may not be done by T-2 theodolite but by something called GPS: global positioning systems. Orbiting satellites will tell you exactly where and at what elevation you are at any moment.
“They say they’re going to phase us field workers out,” James says, “but they say a lot of things.”
What amounts to a catastrophe of technology for field workers should occur in some form within the next four years. It’s perfectly plausible now on paper, but there are problems yet to be resolved. How, for example, do you enter all that data digitally? The amount of information in a single map is huge, and the amount represented by the entire country is virtually unthinkable. Entering it could take years.
The area of cartography perhaps least vulnerable to change is called field completion or revision. Features that are hard to distinguish on a photo must be identified in person. Even a spy photo would not show a dirt road beneath dense tree cover. Field workers must go out and check these details. “Even people in the office don’t know how much work goes into these maps,” says Phil Ibarra. “It takes four to six weeks for a field worker to complete one quad.”
Ibarra is lurching through the rugged hills south of Glenns Ferry, Idaho, in a four-wheel-drive truck. On his lap is an infrared photo of the area that he glances down at from time to time, keeping track of his position. The truck rises and falls over the prairie like a ship at sea. “Right now I’m checking to see if a dirt road from the old map is still drivable,” he says.
It’s not. The truck, an unstoppable-looking beast painted government white, cannot squeeze through a particularly narrow draw. Surveyors have rolled trucks into rivers and nearly driven off cliffs during field completion. One field worker had to walk seventeen miles on an injured leg to get help. Another lost a truck in a flash flood; yet another is famous for setting a stretch of rangeland on fire with an overheated catalytic converter. Still, very few U.S.G.S. cartographers have ever died in the field—or even been bitten by a snake.
Phil is dressed in a bright yellow shirt and a blaze-orange vest. He has been in the field for fifteen years and is loath to leave. “I have crossed every meridian on earth,” he says. “A lot of people don’t like places like this, because it’s just sagebrush. I like it because you’re alone and no one bothers you. It’s a lot of nothing out here.”
Probably the most nothing a person could experience is Antarctica, and Phil has been there twice (he has a T-shirt that says, “Ski the South Pole: 2 miles of base, a ½ inch of powder”). Apparently the exact South Pole moves continuously—that is, nine-thousand-foot-thick ice drifts over it—and the United States periodically sends expeditions to relocate the markers. Phil was on one such expedition; another time he was part of a joint U.S.-New Zealand team that established controls for an area called the Dry Valleys.
For the time being Phil’s job isn’t quite so exotic; he’s simply driving around the Deadman Flat quadrangle with an infrared aerial photo, checking for what he calls “culture.” Culture is anything man-made: houses, gas pipelines, fence scars. Culture includes the Oregon Trail, a century-and-a-half-year-old rut in the prairie that happens to cross the farm road Phil is on. It winds along a dry wash and then over the crest of a hill; the immigrant who bumped over these rocks had another four hundred miles to go before reaching the Promised Land of the coast.