McCarson had always liked the gun-slinging look of Com-stock's Border Patrol agents, and noticed that they often worked without supervision. "That's what really did it," McCarson told me. "Because I liked to hunt and fish, and it looked more like huntin' and fishin' than workin'-they'd give you a vehicle and you were on your own."
When he began tracking, he saw immediately that his hunting skills were almost useless for following people. Border Patrol trainees learn to track informally and opportunistically, tailing journeymen on live trails and asking questions as circumstances permit. McCarson augmented the process by walking exhausted, still-legible trails whenever he could, as far as he could, which is generally encouraged but not frequently undertaken because agents have to do it on their own time.
"Everything you need to know about tracking I can explain in about two sentences," he told me. "You're evaluating the ground for the difference between the disturbance made by humans and the disturbance made by any other force. After that, it's all practice. It's all just looking."
A planetary difference in vision separates great trackers from ordinary trackers. At Brackettville, McCarson and about a dozen other trackers occupy a paramount plane. "There's just a certain level you get to, where you can't say who's better," McCarson says. "And I can't even tell you what that level is as far as particular sign-it's just, if there's something there, we'll see it."
One slow day, after driving the length of a blank drag, McCarson gave me a concentrated lesson. We parked at the edge of a ranch road. In the adjacent dirt, day-old prints held faintly for a while and then disappeared into mesquite. McCarson checked the angle of the sign and pointed at the horizon, toward the group's destination. Then he pointed at a deer trail. "I can see all kinda sign through there," he said, and strolled off to make a cell-phone call.
But there was nothing to see: vacant inflexible earth, sparse mesquite-branch detritus, mesquite leaves in inconsistent profusion, various and occasional flat square-inch plants-beggar's-lice, hore-hound, hedge parsley-and rare tufts of short grasses. All color fell along a drastically shortened mustard-olive-ash continuum. The longer I went without seeing anything, the harder I looked at tiny things close by, and the more obdurately flawless they seemed.
McCarson ambled back. "You wanna see more but you ain't," he said. "That's the maximum the earth's gonna give you." He aimed his cane at some beggar's-lice. I got close and saw that several stalks had been nudged forward and now leaned at a slight angle, maybe thirty degrees from their natural posture. McCarson pointed to two seedpods the size of ball bearings which had exploded under downward pressure. He pointed to a half-inch mesquite twig that listed a little; its bark at the contact point was a fine-particulate smear. He pointed to a piece of ground the size of a playing card: half the stalks in a tuft of buffalo grass were stabbing ardently forward, and the adjoining earth had also been compressed-once spherical granules and clods of soil urged down toward two dimensions-and this compression was continuous and equivalent in degree through the two mediums of grass and earth.
These pygmy symbols were all within six feet, but they were isolated, camouflaged, and enclosed by a lot of pristine terrain-they didn't relate to one another directionally. McCarson waited for a moment while my eyes struggled to absorb them, and then strolled off. My eyes didn't absorb anything. I was afraid to move and contaminate the sign: I'd been immobilized by tininess. From somewhere in the brush, McCarson said into his cell phone, "Did those spearguns come in yet?"
After a while, he came back and pointed to a small area in a patch of mesquite leaves, which are very thin. I couldn't see anything; the leaves appeared to be flush with the ground. Then I got to within a few inches and noticed that they hovered microns above it, as if they'd been levitated by some exceptionally weak force- static electricity raising arm hairs or surface tension holding water above a glass rim. McCarson's area-he kept his cane trained on it-was composed of undamaged leaves that were truly flush with or partially embedded in the earth. The compacted region was a few inches long and about the width of a shoe sole.
"See those dingleberry bushes?" McCarson said. They were the size of Ping-Pong balls, and from a distance I couldn't tell that they'd been crushed: in two dimensions, they retained their fundamental color and some unbroken seeds and a remnant network infrastructure, the way road-killed toads can look like living toads minus a dimension. Up close, I saw fine fragmentation and a uniformity of flattening-a broad pad of compression-that only a shoe, not an angular hoof or a puncturing paw, could have made.
Sign cutting is overwhelmingly hushed and uneventful, but the screen of the ground shows action. Trackers find bits of skin and sock on the fishhook spines of horse-crippler cactus and watch the stride transformation and inexorable decline in mobility as the injury worsens. They watch as groups exhaust themselves and start resting more frequently, and as disoriented or fractious groups splinter. The day after a moonless night, the ground shows walkers equivocally chafing their way through mesquite thickets.
Agents watch as weak people stop so that everyone else can go on, and as they later stand up and try to keep going or give up and try to get caught. Very occasionally, in summer, the ground leads Brackettville agents to corpses. Death in the brush is notable for the attempts that dying people make to undress: a dehydrated, overheated body swells as death approaches, so the dying remove their shirts and shoes and socks, and unbuckle their belts. They seem to find comfort in order, folding items of clothing and arranging their belongings. They prefer to die under the boughs of trees, on their backs.
After a few nights sleeping in the brush, people emanate an odor of campfire smoke and sweat that can float for hours over an abandoned campsite. In wetter weather, the smell of canned sardines persists for a day. Cutting trails, agents step over shit and piss and blood and spit. They find handkerchiefs, pocket Bibles, bottles of Pert Plus, and photographs of daughters with notes on the back ("Te extrano. Regresa a casa pronto. Te Amo, Isela"). They find message-board graffiti on water tanks ("23/2/03 Por Aqui Paso Costa Chelo Felipe L. Miguel"), and the roasted remains of emus, doves, jackrab-bits, and javelinas. The great majority of illegal immigrants are adult men, but sometimes agents find diapers and tampons and tiny shoes.
As trackers move through diffuse fields of abandoned objects, fixing the age of the sign, they assure themselves that they're walking through a group's recent past. They want to walk right into its present. They want the sign to turn into its authors. On live trails, the metamorphosis feels imminent, because it always could be. Groups stop unpredictably; if your group lays up at the right time, you'll find yourself disconcertingly deep in a marginal trail yet two minutes from an arroyo filled with snoring. The people you're chasing might appear on the other side of every rise you crest.
Because sign is so shifty and strongly insinuating, it's hard to avoid equating the trail with the people it evokes. Trackers say they're "running" or "chasing" a trail; they say they just "caught" a trail; they say, "That trail got away." The language of tracking treats the sign at the leading edge of a trail as the group itself. After cutting a trail's frontier, trackers say things like: "They're in this pasture," or "They're right there trying to find a good spot to jump the fence," or, simply, "They're here."