From “Fine Disturbances,” The New Yorker
United States Border Patrol operations above the Texas stretch of the Rio Grande often begin with a single agent on foot, staring at the earth. In the Border Patrol, tracking is called cutting sign. ‘Cutting’ is looking; ‘sign’ is evidence. No technology is involved. Trackers look for tread designs printed in the soil and any incidental turbulence from a footfall or moving body. They notice the scuff insignia of milling hesitation at a fence, the sudden absence of spider webs between mesquite branches, and the lugubrious residue of leaked moisture at the base of broken cactus spines (the dry time is a stopwatch). The best trackers know whether scatterings of limestone pebbles have come off human feet or deer hooves. They particularly value shininess—a foot will compress the earth in one direction, which makes it shine, and wind quickly unsettles this uniformity, so high-shining groups are irresistible…
Cutting sign 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 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 belongings. They prefer to die under the boughs of trees, on their backs.
After a few nights of 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 and pocket bibles and 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, jackrabbits, and javelinas. The great majority of illegal immigrants are adult men, but sometimes trackers 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 immigrants you’re chasing might appear on the other side of every rise you crest.