"Whenever the soil is disturbed, there's a faint color change." Mike Crelia peers at the tracks of workboots that head through a thick stand of tamarisk and up an embankment. "Fresh sign will actually be a different color than when it's a day or two old. And even if there's no wind, there's always insect activity. Ants will walk across the footprints, or other insects will, and they leave sign of their own. You can gauge how old sign is by the amount of insect tracks across it. This guy came through here not long ago. Maybe a couple hours."
We crawl, stooped over, through tunnels in the tamarisk. Crelia, Public Lands Liaison Agent with the Border Patrol's Wellton, AZ office, sweats only a little in the 114-degree afternoon sun. An Oklahoma native who's lived in Yuma for eight years, he's used to the heat. "This stretch of land between here and the river is pretty much a no-man's land," he tells me. "It used to grow crops, but nothing can grow here now. The aliens hole up here after they come across the river and then they try to make a break for it. If they make it into that settlement over there, Gadsden, then it's much harder for us to apprehend them."
Gadsden is a small Arizona town--a housing development really--a dozen miles southwest of Yuma, half a mile east of the Colorado River and Mexico. Between the river and Gadsden lies a gauntlet. Above the tamarisk bosque is a levee road, its shoulders 20 feet of dust on which a set of workboot tracks would stand out boldly. (The Border Patrol grooms the shoulder regularly, dragging bars weighted down with tires. Any sign on this road is fresh.)
Across the road is a wastewater canal with steeply sloping concrete banks. A desalination plant in Yuma removes salt from local agricultural runoff before it's discharged into the Colorado River. The wastewater canal carries the extracted salt to the Sea of Cortez. Migrants must cross the canal, either by way of heavily monitored bridges, or by swimming it. A week from today, four migrants will attempt to swim the canal. Three will make it. Its steep banks and deceptively swift water claim lives on a regular basis.
Beyond the canal is another road, also dragged regularly by the Border Patrol, and an empty field with furrows parallel to the canal. Footprints show readily against the plowed soil. Border Patrol vehicles cruise up and down both sides of the levee, and remote-controlled cameras atop high platforms sweep the area. Border Patrol agents and National Guardsmen monitor the cameras from an air-conditioned room in Yuma. At night, the cameras automatically switch to infrared, sensing the body heat of any living thing walking across the field.
It seems unlikely that anyone could make it across the barrier here, but people do: hundreds of them a year. And they leave their mark on the landscape. "It looks like they've been building here," says Crelia, pointing to a thatch hut made of tamarisk branches. The entire thicket, several miles long, seems shot through with crawling tunnels and branching paths. Except, that is, where it has been burned. "They'll set fires sometimes as a diversion," says Crelia. We'd just driven past one patch that had burned for a quarter mile to the river. Where the bosque is unburned, a staggering amount of trash lies on the ground. There are plastic water jugs, discarded soda cans, and sports drink bottles. There are trash bags. "The aliens put their clothing in the bags to cross the river," says Crelia. "When they get across, they put the clothes back on and leave the bags." A large proportion of the clothes get left behind as well, from the looks of the place, as well as what Crelia calls "foam shoes": blocks of foam or carpet the migrants wrap around their feet to obscure their tracks. There are Kleenex boxes here as well, presumably used for the same purpose.
The trash literally extends as far as the eye can see. It's safe to assume that among the plastic and fabric and cardboard lies abundant human waste, given the continuous presence of people waiting for hours, perhaps days, for a chance to run into the United States. …