The Watch

The Texas Border Volunteers are working to curb the growing number of illegal immigrant crossings into South Texas.

(Lauren Fox for USN&WR)

The Texas Border Volunteers look to stop immigrants from crossing into the state illegally.

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FALFURRIAS, Texas – Just before sundown, a group of men cloaked in camouflage from the Texas Border Volunteers halts their all terrain vehicle, along a winding sandy road. As they make their way around the heavy brush, they circle around a pile of women's undergarments, which lay at the foot of a tree. In sections of land near the U.S.-Mexico border, this is known as a "rape tree." And for the residents of Brooks County, Texas, rape trees are popping up at an alarming frequency.

"I've had three rape cases in the last month," says Benny Martinez, the chief deputy at the Brooks County Sheriff's Department. "These guys are animals. There is an intimidation factor there. If they don't give into the brush guide, [the women] get beat up."

The group who found the "rape tree" are part of the Texas Border Volunteers, a troop of a few dozen private citizens who spend their own time – six or seven hours at a clip – weaving through the low-hanging honey mesquite trees and heavy Texas brush looking to stop immigrants from crossing into this land – and their country – illegally.

Symbols like the rape tree serve as a reminder to volunteers or anyone passing through of the escalating brutality "coyotes" are using to control immigrants they lead through this land. The tree is a trafficker's way of asserting power. But it also serves as a landmark for the border volunteers, allowing them to keep record of immigrant migration patterns through the brush.

When the Texas Border Volunteers head into the muggy summer night, each member gathers night vision goggles, flashlights, guns and folding chairs.

They run their shift as if they had been given marching orders from a commanding officer. They run their operation like a military mission, with code names like "gumball" and "pole cat" buzzing across their walkie-talkies.

[READ: Immigration Reform and Getting Border Security With Mexico Right]

For them this is a job, and they take it very seriously.

A team of Texas Border Volunteers gathers to finalize their plan before assuming their positions in the dense Texas brush and waiting for immigrants to cut across their fields.

Founded in 2006, the Texas Border Volunteers began as a citizen response to the growing amount of property damage occurring on the wide swath of private ranch land in Brooks County, Texas, an area 70 miles north of the U.S.-Mexico border. The county is home to the final border patrol checkpoint before human and drug smugglers funnel their inventory north. To get around the border patrol station, drivers often unload their cargo on desolate county roads and smuggle it through the dusty Texas fields for dozens of miles where they can hide among the thick landscape, sometimes for days.

The volunteers who patrol the ranch lands come from all walks of life; a mix of retired military personnel, educators, small business owners and computer technicians. While some live in the area, others come all the way from north Texas, or even out of state, to lend a hand. When they aren't on patrol, they sleep in a garage bunker or in tents on the ranch.

Veterinarian and rancher Michael Vickers, who has lived in Brooks County since 1986, founded Texas Border Volunteers out of desperation.

"They started cutting our fences and they broke into my house and tore up our water sources, breaking the floats off. And it has just been escalating," Vickers says. "The groups are getting bigger and the people are more combative."

Vickers' wife, Linda, never leaves the house without her cell phone, a gun and her four guard dogs.

Ranchers in the area say immigrants used to pass through without much of a trace.

"It used to be mostly Mexican peasants coming to look for work," Vickers says. "Maybe a couple times a week, they'd show up at my front door, ring the doorbell and ask if I had any work for them. If I didn't, I'd send them across the road or point them in the direction of work. They were very respectful. We'd give them water, we'd give them food."

Now, all along Route 281, bended fences, abandoned clothing and empty Gatorade bottles lay scattered on the road, evidence of groups passing through.