The Last Datum

The Projection

Chapter 1: The Last Datum

The theodolite weighed fourteen pounds and had outlasted two marriages in the Survey, though only one of them was his. Silas lifted it from the foam-lined case the way he had lifted it six hundred times before, checking the tangent screws with his thumb, turning the horizontal circle until the vernier read zero, then locking it and setting it back in the foam. The case was olive drab and dented along the south-facing edge where it had fallen from a packboard on the Chandalar River in 2014, and the dent had become part of the instrument's identity, the way a scar becomes part of a face. He closed the latches. He wrote the serial number on the equipment manifest even though he knew it from memory the way he knew his own Social Security number and Margot's birthday and the elevation of Denali to the nearest foot: 20,310, revised downward by ten feet in 2015 after the last precise survey, a number he had watched change in his lifetime and which reminded him that even the highest fixed point on the continent was not actually fixed.

The manifest was a Form 9-1380, printed on government stock, and he filled it with a mechanical pencil because ink bled when it got wet and everything got wet in the Brooks Range eventually. Theodolite. Tripod. Stadia rod, two sections. Brunton compass. GPS receiver, Trimble R10, serial number noted. Battery packs, four. Solar panel, folding. Rite in the Rain notebooks, one dozen, number 373, the universal field book with the green cover and the pages that would take graphite in a downpour. Rapidograph pens, sizes 00, 0, 1. India ink, one bottle, Higgins Eternal, which was a name Margot had once found funny.

He stopped writing.

The house was quiet in the way that houses with one person in them are quiet, which is not silence but the particular acoustic signature of absence. He could hear the refrigerator compressor cycling in the kitchen and, through the closed window, a Steller's jay in the spruce outside. The window faced north, toward the Alaska Range, though from this room he could see only the neighbor's roof and, beyond it, the tops of birch trees that had not yet leafed out because it was the first week of June and spring came to Fairbanks reluctantly, unpacking itself over weeks rather than days, as if it too had a manifest to check.

He put the pencil down and looked at the manifest. He had been filling out equipment lists for thirty-eight years, first as a field assistant and then as a party chief and finally as a senior cartographer who went into the field less and less frequently because the field was being replaced by satellites and photogrammetry and LiDAR, by data that arrived on servers without anyone having to stand in the rain holding a stadia rod. The manifest was an artifact. The theodolite was an artifact. He was an artifact.

This did not trouble him. What troubled him was the room behind the closed door at the end of the hall.

He returned to the manifest. Sleeping bag, rated to minus twenty. Tent, two-person, Mountain Hardwear. Cook kit. Water filter. First aid kit, USGS standard issue plus the additions he had made over the years: extra moleskin, a SAM splint, the prescription ibuprofen that his knees now required after a day of walking uneven ground. He was sixty-three. His knees knew it. His back knew it. His eyes, which had spent nearly four decades reading fine graduations on brass circles, knew it intimately.

The Fairbanks office had not required him to file a medical clearance for this trip because Ruth Atwood in Anchorage had waived it. Ruth understood that requiring a sixty-three-year-old cartographer to get a physical before his last field season would be an act of bureaucratic cruelty, and Ruth, despite twenty years in federal management, had not yet learned to be bureaucratically cruel. She had approved the survey of the unnamed tributary of the Koyukuk on the strength of a one-page proposal that Silas had written in February, sitting at this desk, looking at this window, not looking at the closed door. The proposal said the tributary had never been formally surveyed. It said the existing topographic coverage was derived from 1:63,360 quad sheets compiled from aerial photography in the 1950s, with contour intervals of one hundred feet, which was adequate for the scale but left the actual drainage unmapped at the level of detail that mattered. It did not say what mattered meant. It did not say why, in his last season, he wanted to map a creek that no one had asked about, that served no navigation purpose, that drained a watershed too small to appear in any water resources inventory. Ruth had approved it anyway.

Silas suspected she had approved it the way you approve a last request.

He finished the manifest and set it aside and opened the map tube. Inside were three sheets of vellum, blank, rolled, waiting. Vellum was translucent and strong and took ink without bleeding and could be reproduced by diazo or scanned at high resolution, and it was what he had always drawn his finished maps on, even as the rest of the Survey moved to digital cartography, to GIS databases, to files that existed nowhere and everywhere simultaneously. The vellum was real. You could touch it. You could hold it to the light and see through it, which was the property that made it useful for overlays and also, he sometimes thought, a metaphor that he was not quite willing to pursue.

He set the vellum aside. He checked the Rapidograph pens, running each one across a scrap of paper to verify the ink flow. The 00 drew a line 0.30 millimeters wide. The 0 drew 0.35. The 1 drew 0.50. At 1:24,000 scale, which was the scale he intended to use, a line 0.50 millimeters wide on the map represented twelve meters on the ground. Everything on the map was wider than it was in reality. Every river was broader, every trail thicker, every contour line a band rather than the infinitely thin mathematical curve it was supposed to represent. The map was always a lie, but it was a useful lie, a disciplined lie, a lie that told you the shape of the truth even as it distorted the truth's dimensions.

Margot had understood this. She had painted the same landscapes he mapped, and her paintings were also lies, but lies of a different order. She added what the map subtracted: color, atmosphere, the quality of light at a particular hour. Her palette was the Brooks Range in August, umbers and ochres and the grey-green of tundra lichen, and she mixed her colors the way he mixed his data, combining raw observations into a representation that was not the thing itself but was, if done well, faithful to the thing in the ways that mattered.

He was thinking about Margot's palette and he had not meant to think about Margot at all, and this was the problem with the house, with staying in the house. The house was full of her paintings. They hung on the walls of the living room and the hallway and the spare bedroom and even here, in his study, where a small watercolor of the Tanana River in breakup hung above the bookshelf, the ice going out in April, the water brown and heavy with sediment, the sky the color of a dirty eraser. She had painted it in 2016 from a photograph she took from the Cushman Street Bridge, and he had been with her when she took the photograph, and he could reconstruct the exact date from the stage of breakup: April 28, plus or minus two days, because the river's calendar was more reliable than his memory.

He did not look at the watercolor. He looked at the manifest.

The field assistant was a young man named Jin Park who worked in the Anchorage office and did GIS analysis and had requested field experience because, Ruth said, he wanted to understand where the data came from before it became data. Silas had agreed to take him because Ruth had asked and because it was difficult to refuse Ruth and because, if he was honest, he did not want to go alone. He had gone alone many times. He had spent weeks in the field with no company but the landscape and his instruments, and he had found the solitude not just tolerable but necessary, the way a particular projection is necessary for a particular purpose — the solitude preserved something that company would have distorted. But that was before Margot died, and now solitude had a different quality, a different shape. It was no longer the solitude of a man whose wife was at home. It was the solitude of a man whose wife was nowhere.

He pushed back from the desk and stood. His left knee protested with the specific grinding sensation that his doctor called crepitus and that Silas, privately, called the sound of cartilage reading its own contour map. He walked to the kitchen and filled the kettle and stood at the window while it heated. The yard was mud and snowmelt. The fireweed had not come up yet. Margot's garden beds, which she had maintained with the same careful attention she gave her palette, were overgrown with last year's dead grass, and he had not cleared them because clearing them would be an acknowledgment, and he had made enough acknowledgments.

The kettle boiled. He made coffee, instant, Folgers, because the French press had been Margot's instrument and he did not use it for the same reason he did not enter her studio. The closed door at the end of the hall was the door to her studio. Behind it were her easel, her paints, her brushes, her turpentine, her rags, her unfinished canvas. The unfinished canvas was a painting of the Brooks Range, the view north from Atigun Pass, the sweep of tundra falling away toward the Arctic plain, and she had been working on it when the diagnosis came, and she had not gone back to it, and neither had he.

He drank the coffee standing up. He looked at the equipment spread across the study floor: the cases, the packs, the notebooks, the vellum tubes. In three days Carl Driscoll would fly him and Jin Park to the gravel bar on the Koyukuk, two hundred miles north, and he would set up camp and begin surveying the unnamed tributary, and for three weeks he would do the work he had always done, the work of reducing a landscape to its essential geometry — contour, distance, elevation. He would measure. He would record. He would bring the measurements home and draw the map. The last map.

He did not think of it as the last map in a sentimental way. He thought of it as the last map in the way that a series has a final term. Every career was a finite sequence. His was ending. The map would be drawn and filed and digitized and added to the national topographic database, and it would be indistinguishable from the thousands of other maps in that database except that it would be the last one made by a man who had spent his life making them, and that distinction would matter to no one but him.

He rinsed the mug and set it in the dish rack and went back to the study.

The Trimble R10 was in its yellow case on the desk. It was Jin's instrument, technically, though Silas would carry one too, a Trimble R8 that was older but still within spec. The R10 was faster and more accurate and connected to more satellite constellations — GPS, GLONASS, Galileo, BeiDou — and could determine a position to within eight millimeters under ideal conditions, which meant conditions that did not exist in the Brooks Range, where the terrain blocked satellite signals and the ionosphere was disturbed by the aurora and ideal was a word that belonged in a manual, not in the field.

Silas opened his own GPS case and checked the battery. The R8 determined positions to within fifteen millimeters under ideal conditions, which was worse than the R10 but better than anything he had used for the first twenty-five years of his career, when positions were determined by triangulation from known benchmarks, by measuring angles with the theodolite and distances with a steel tape or an electronic distance meter, by calculations done by hand in the field notebook and checked at night by lamplight. Those positions were accurate to within a few centimeters if you were careful and within a meter if you were not, and the maps made from them were accurate enough to hike by, to fly by, to fight a fire by, and no one had complained.

The difference between fifteen millimeters and eight millimeters was seven millimeters. On the ground, seven millimeters was the width of a pencil. On the map, at 1:24,000 scale, it was invisible. It was the kind of difference that mattered to the data and not to the map, and this was the distinction that Silas suspected Jin Park did not yet understand — the distinction between precision and representation, between the measurement and the thing the measurement was for.

But he would learn. They always learned, the young ones, if they came to the field. The field taught what the office could not, which was that the map was not the territory, that the data was not the landscape, that the contour line was a human invention imposed on a surface that did not contour, that flowed and crumbled and froze and thawed and did not care whether you measured it or not.

Silas closed the GPS case. He taped the manifest to the top of the theodolite case with blue painter's tape. He began packing the duffels.

The work was methodical and he gave himself to it with the attention he had always given to preparation, which was the phase of fieldwork that most determined whether the subsequent phases would succeed or fail. A forgotten battery pack could cost a day. A leaked bottle of ink could ruin a notebook. A sleeping bag rated to zero instead of minus twenty could, in the Brooks Range in June, where the temperature at three in the morning could drop to fifteen degrees Fahrenheit in the shadow of a north-facing ridge, kill you. He did not think about death casually, but he thought about it precisely, the way he thought about all risks — as a function of probability and consequence, both of which could be reduced by preparation.

He packed the duffels. He checked the duffels against the manifest. He added the items he had not put on the manifest because they were personal and the manifest was government property: the photograph of Margot that he kept in a ziplock bag inside his field notebook, the bottle of Lagavulin that Carl Driscoll expected as payment for the flight in addition to the fuel reimbursement that USGS provided, the copy of Barry Lopez's Arctic Dreams that he had carried on every field season since 1993 and had read four times and would not read a fifth but carried anyway because the weight of it in his pack was part of the field experience now, inseparable from the weight of the theodolite and the notebooks and the sleeping bag.

The photograph of Margot was from 2009. She was standing at the edge of a lake in the Wrangell Mountains, holding her paint box, smiling at something off-camera that he could not remember. She was fifty-four in the photograph. Her hair was grey and cut short and the wind was blowing it across her forehead. She was wearing the red fleece jacket that she wore in the field and that still hung in the closet in the bedroom, and he had not moved it because moving it would be an acknowledgment.

He put the photograph in the ziplock bag. He put the ziplock bag in the field notebook. He closed the notebook.

The evening light came through the north-facing window at a low angle, casting long shadows across the equipment on the floor. In Fairbanks in June the light lasted until midnight and returned by two and in between was a dusk that was not dark, a grey interval that could not decide whether it was the end of one day or the beginning of the next. Silas had lived in this light for thirty-five years and it was the light he understood best, the light that made the Brooks Range possible — not the dramatic alpenglow of the tourist photographs but the long, flat, measuring light of the solstice, the light that revealed every contour and cast every shadow and made the theodolite readings reliable from five in the morning until ten at night. It was the light of work.

He stood in it. He looked at the equipment. He did not look at the door at the end of the hall.

Tomorrow he would drive to the USGS office on University Avenue and sign out the government equipment and fill out the travel authorization and confirm the flight with Carl. The day after that he would meet Jin Park, who was flying up from Anchorage, and they would go over the survey plan and the safety protocols and the communication schedule. The day after that, Carl would fly them north.

Three days. Then the field. Then the work.

He turned off the light in the study. He walked down the hall. He passed the closed door without stopping, the way he had passed it every day for two years, and the door was white and the knob was brass and the door was shut and behind it was the easel and the unfinished canvas and the brushes that still held the pigment of the last color Margot had mixed, which was a blue-grey that she called glacier light, and the studio smelled — he imagined, he did not open the door to verify — of turpentine and linseed oil and the particular dusty warmth of a room that received south-facing sun through a large window and had not been opened in two years.

He went to the bedroom. He set the alarm for six. He lay in the bed that was too wide, on the side that was his, and the other side was empty, and the sheets on that side were clean and tucked and had been clean and tucked for two years.

He closed his eyes.

In three days he would be in the field, where the only surfaces that mattered were the ones he could measure, where the only distances that mattered were the ones between benchmarks, where the only curves were the contour lines he would draw to represent the shape of ground that had existed for ten thousand years without a map and would exist for ten thousand more after the map was drawn and filed and forgotten.

The map would preserve the shape of the land. That was what maps did. They preserved one thing — shape, area, distance, direction — by sacrificing the others. No projection preserved everything. You chose what mattered, and you accepted what was lost.

He had chosen.

He slept.

Outside, the light did not end. It lay across the birch trees and the mud yard and Margot's untended garden beds and the roof of the house where the paintings hung on every wall, and it held all of it in the long, level, unsparing illumination of the subarctic summer, where nothing was hidden and nothing was dark and the only shadows were the ones cast by objects that stood between the light and the ground, which was the definition of a shadow and also, if you thought about it long enough, the definition of a life.