I think perhaps the clearest description of the challenges that migrants face who are trying to enter the States illegally is shown in the opening paragraph of this powerful text. Note how the five men are depicted and what this says about the dangers implicit in trying to take the Devil's Highway into the States:
Five men stumbled out of the mountian pass so sunstruck they didn't know their own names, couldn't remember where they'd come from, had forgotten howlong they'd been lost... They were burned nearly black, their lips huge and cracking, what paltry drool still available to them spuming from their mouths in a salty foam as they walked. Their eyes were cloudy with dust, almost too dry to blink up a tear... They were drunk from having their brains baked in the pan, they were seeing God and devils, and tehy were dizzy from drinking their own urine, the poisons clogging their systems.
One of the most horrific aspects of this text is the way that Urrea spares nothing in terms of describing the impact of dehydration on the human body. He goes into exact and precise detail of each stage of this process, imagining what the walkers might be thinking and feeling and focusing in on their internal organs and what is happening inside of them. This is by far the biggest challenge facing migrants choosing to enter the States through this way, as the many corpses that litter this patch of desert amply demonstrate. The territory is described variously as "unforgiving" and "relentless" and "vast," and for a human to choose to walk through it would be a very big risk indeed.