As the U.S. government has militarized the California and Arizona segment of the Southwest border over the last two decades, illegal crossers have moved to another area. South Texas has become the new border hot spot.
The Rio Grande Valley is also the closest route to Central America. Two-thirds of those caught crossing are from that troubled region.
The Border Patrol and local authorities are straining to keep up.
Fleeing Poverty And Murder
In Reynosa, Mexico, just across the Rio Grande from McAllen, Texas, is Casa del Migrante, a Catholic-run shelter.
It's a cement-block building with a large dining room, separate dorms for men and for women and children. It's a relatively safe place in what can be a dangerous city for migrants like Mario Torres.
The soft-spoken 25-year-old has already traveled 1,500 miles from his home in Honduras. He paid fees to guides and bribes to bandits. Better than staying home, he says.
"I couldn't find work," he says. "I came with my wife. We came together, the two of us. The criminals, they killed one of her brothers. We had to come because they were threatening us."
Torres was a truck driver; his wife was a high school teacher. He says they had no choice but to escape the poverty and violence in Honduras, the country with the highest murder rate in the world. His wife is already in the U.S., with relatives in South Carolina.
They paid smugglers a premium price for her to cross safely: $13,000.
"I have a cousin in the United States," Torres says. "She loaned us the money, and now she's working my wife started working and paying it back, little by little."
Now he's biding his time until he can cross. He'll need to pay a guide to ford the Rio Grande on a power boat, an oar boat, anything that floats.
On the U.S. side of the river, Border Patrol Agent Danny Tirado drives along a landscape that is very different from the Arizona desert the stretch of border that's gotten most of the attention over the last decade.
In Arizona, steel walls and mountain ranges separate the seemingly endless desert between the two countries. Here in South Texas, the border wall doubles as a levee to protect McAllen from flooding.
Outside the city, the wide Rio Grande is the barrier, though it twists and turns so much that, in places, border agents can't see around the next bend. The air is humid, the vegetation thick.
"It's a lot of dense brush," Tirado says. "It does make it easy for people to hide in that area."
'I Don't Feel Safe Anymore'
The Border Patrol has been beefing up its presence here. Over the last decade, it has doubled the number of agents in the Rio Grande sector to roughly 3,000.
The Border Patrol even has a checkpoint 65 miles north of the border, in Brooks County, Texas, on the main road out of McAllen. Every vehicle stops at there an effective way to catch drug smugglers.
Few migrants try to cross, however. Instead, human smugglers stop before the checkpoint and tell their clients to walk around it, right onto Linda Vickers' ranch land.
"I don't feel safe anymore out here," Vickers says. "I carry a pistol with me and cell phone when I go outside. It just shouldn't be like that."
The Border Patrol checkpoint is Vickers' nearest neighbor, about 4 miles away. The ranch is in grassland dotted with mesquite trees and scrub brush. As she sits on the front porch of her large stucco ranch house, her dogs stand at alert, sensing something.
"I guarantee you, they smell somebody," Vickers says.
She sees groups of 10, 20, even 50 people every day, she says.
"It's the trespassing. It's like if you had a nice yard in a nice place, and people were littering and tearing your fences and defecating on your property," she says. "And you're finding all this you'd be a little upset, too."
Crossing Can Be Deadly
It's easy to see why people cross here. If they make it to the next pickup point, they've pretty much made it to anywhere in the U.S. But it's not a quick walk around the checkpoint, as smugglers tell the migrants.
People can be out in the heat or the cold for days before they're picked up again.
Brooks County Chief Deputy Sheriff Benny Martinez sees the bodies of those who don't make it. Last year, 87 people died crossing Brooks County. He calls that good news.
"I call it good news, absolutely," Martinez says. "Compared to last year's 129, we're way down."
He says deaths declined only because the weather was relatively mild.
Overwhelmed And Frustrated
Martinez's office is in the Brooks County seat, Falfurrias. It's a small town in a small county of fewer than 10,000 people.
Martinez and his four deputies are used to dealing with relatively small matters: traffic, drunkenness, the occasional burglary or fight. Now, he says, dealing with illegal crossers takes up more than 85 percent of the sheriff's office workload and half the county budget.
"It's been overhwelming," Martinez says. "It's been frustrating, frustrating in the sense that you're trying to do what's right and you can't because [you] don't have the resources to do it."
Brooks County doesn't even have a medical examiner for the bodies, relying on a neighboring county and on Texas State University to do autopsies and DNA tests so the dead can be connected with their families.
Martinez says he'd like to see the federal government pass a guest worker program so people can come legally. In the meantime, Brooks County is asking the government to reimburse its costs.
"It has to come from Washington," he says. "I don't see Brooks County taking the whole burden of all of this. It just doesn't make sense."
It fits the government's strategy, though: Increase border security in one place so people cross in another until it becomes too dangerous or too expensive.
But, they keep coming.