So many wrinkles on the map. All that saguaro and creosote bush, ironwood, mesquite, and the occasional and most blessed cottonwood. Hawks, eagles and vultures. Big cats hunting tiny deer. A few dozen endangered Sonoran pronghorn, grazing the thin promise of the 21st century.

To the true rat, the map says come hither, stay awhile.

Well, maybe not right now. In June and July, the big empty along the U.S.-Mexico border is among the most merciless environments on Earth. The sun roars down though the long days, patiently trying to kill every living thing foolish enough to skitter under its arsenal of photons, neutrinos and UV rays. Temperatures spike at 110 or even 120. Shade is scarce. And don't put that thermometer on the ground - you'll blow the top off. After midnight the air cools down to maybe 90.

Desert rat or not, anyone who looks at this specially drawn map will surely appreciate the point made by what looks like black pepper all over the thing: people die out there, lots of people.

Each speck of black designates the end of a trail - the precise spot where hope has become desperation, and then changed finally into something else - something none of us can know for sure until we finally meet it.

The map shows that from 2001-2007 the U.S. Border Patrol recorded 1,058 migrant deaths north of the border. Lots more people die and don't get found, of course. It's a big desert.

Sometimes groups of a dozen or more go down together, stumbling up hills and staggering down washes until each can finally do no more, and the heat takes over.
The accounts of survivors and the quickly-mummified evidence on the ground suggest that a cooked brain and water-starved sensory neurons must know something of hell. The mouths stuffed with rocks, the claw marks - it happens. There are files.

The U.S. government's Southwest Border Strategy, begun in 1994, deliberately pushed smuggling and immigration routes out of cities like El Paso and San Diego and into remote, rugged desert areas like southern Arizona. According to a 2001 report by the U.S. General Accounting Office, the goal was "to make it so difficult and costly for aliens to attempt illegal entry that fewer individuals would try."

That strategy - amped up with other gung-ho post-Nine-Eleven initiatives - has led to militarized Border Patrol bases, billion-dollar fencing plans, and birdwatchers getting buzzed by Blackhawk helicopters. What it has not done is reduce illegal immigration.
A mind-boggling flood of people are coming north through the once-quiet desert. How many? On average, the Border Patrol's Tucson Sector alone apprehends some 1,200 migrants daily. Perhaps three times that number succeed. That's more than a million people a year.
Hundreds die. Meanwhile, the national debate over social and economic impacts of illegal immigration becomes more shrill and abstract.
The argument includes such "peripheral" issues as impacts on wildlife from low-flying helicopters, Humvee traffic, and a 700-mile-long fence. Environmentalists say the Sonoran pronghorn and the occasional jaguar or ocelot will either cross our militarized political boundary, or die trying.
All of this was on my mind in early March when I took a quick trip to the Sonoran desert south of Tucson. The annual explosion of brittlebush, globemallow, and poppies had begun. The killing heat had not arrived. Soft air brushed my skin like birds' wings.
The land looks empty at first. But the washes are lined with human footprints by the thousands - all heading north. I stepped over abandoned clothing, backpacks, and hundreds of empty water bottles.
I didn't see any migrants (they typically travel at night, unless in desperate condition). But I could feel them around me, shaded up and waiting for darkness to fall again.

These armies of the night will continue to march. Like the desert beasts, they are driven by hunger. They do not care about borders, fences, or political and economic arguments. Neither would I. They will eat, or die trying.