It's hard enough to drive through the Arizona desert, where the sun is harsh and the distances immense. This is the story of people who walk it.
In particular, it's the story of Brenda, who asked us to use only her first name. She told us yet another of the unbelievable stories you hear in the Borderland.
We met her in Nogales, Sonora, on the northern border of Mexico opposite Arizona. She was living in a shelter for deported people, where she told us of her brief and difficult stay in the United States.
She'd come all the way from southern Mexico, and crossed the border into Arizona early this year. Then her group of migrants was spotted by the U.S. Border Patrol somewhere outside of Tucson. How did she escape? "I ran," she said simply, but she was separated from her group, and was soon lost in the desert.
Outside settled areas, southern Arizona features stark mountains and cactus-filled valleys, breathtakingly beautiful but difficult to survive in. In this landscape, she wandered for three days.
"I kept seeing lights," she said. "I'd walk toward them but get no closer." She was, she said, "dying of hunger." And she might have actually died except that in all that vastness, she discovered a discarded cigarette lighter.
She used it to light a brush fire so that she might be spotted by the Border Patrol helicopters flying over the area.
The desert had become so intolerable that she was, she admitted, all but begging the Border Patrol to come and remove her from the country.
Arizona remains a major corridor for cross-border smuggling and migration, though much of the traffic has shifted eastward to Texas. Improved border fences in recent years have made it harder to bring vehicles across some of the border fences are built using recycled train rails. Such fences do not stop people on foot; for them, the true barricade is nature.
Some of the most severe territory is also some of the busiest: near the Tohono O'odham reservation that straddles the border. Here we met Malcolm Lewis, the public safety director for the Tohono O'odham Nation.
He has a chart depicting scores of dead people found year by year on tribal land. "Our highest was 125, which is really a real burden on us because of the possibility of it being a homicide," he said.
Investigators have to determine whether the deaths were caused by the elements, or by people.
We took a drive in the desert with tribal public safety officer Lt. Michael Ford, who has spent 17 years on this police force, though he's not a member of the tribe. He's an African-American from Michigan who has gradually learned this landscape.
"When people cross these mountain ranges here, those are huge mountains. And it takes awhile to get out there to do the recovery, and bring people back," he says.
He knows from experience: Collecting bodies was the job of the last unit he supervised.
"The way I always like to look at it is, the worst possible scenario already happened. That person lost their life. They're gone," he says. "At least you can help them get back to where they belong to and help somebody somewhere have some resolution and have some closure for something that happened."
There are always some bodies that are never claimed, though.
"It's like an ocean. And there's just some people that are lost at sea that you're never going to find," Ford says.
Driving along the border fence, we saw many signs of people who had tried to prepare themselves to cross it. The area was littered with empty water bottles.
People also left signs that they were avoiding detection. Once, we stopped to look at a pair of overshoes made out of white carpet, which could hide tracks along the roadway.
These carpet shoes were discarded right by some tire tracks.
Yet the same people who try to hide from the authorities sometimes end up needing them, like Brenda, who set the fire to signal the Border Patrol in the desert. The Border Patrol says in the last fiscal year, it rescued 2,346 people from lost hikers to lost border crossers.
As we drove the border fence, Ford pointed out yellow warning signs: "Don't expose your life to the elements; It's not worth the trouble," one reads in Spanish.
Smuggling organizations, people known as coyotes, push groups of migrants through harsh territory at a pace the migrants might not expect.
Yet even people who know the journey sometimes find it worth the risk.
After being rescued from the desert, Brenda ended up resting on the Mexican side of the border at Nazareth House, the shelter for deported women in northern Mexico.
Asked whether she meant to cross the border again or give up and return south, she said she'd go south.
But then she gave it some thought.
"Maybe later," she said. "Maybe later I'll try again."