As illegal border crossings have shifted from Arizona to Texas, the surging tide can be measured with grisly markers -- a growing number of skeletal remains being recovered and interred in unmarked graves.
For many the covert trip through Brooks County, 70 miles from the Rio Grande Valley border crossing, has become a death trap of temperatures in the triple digits, thick mesquite brush and sand that is a foot deep in places.
While Congress struggles to fashion a reform of the immigration law that could include more officers to patrol the border, a Baylor University professor and her students have taken on the grim task that no one else has tackled -- identifying the dead.
They are excavating the bodies --dozens so far -- cleaning them down to the bones and preparing them for DNA in an attempt to put names to the bodies and reunited them with their families.
With no identification on them, not even a country of origin, the Baylor team plans to use forensic science to gain profiles of the dead. That information will be entered into a national database with the hope that it will help families of the missing know what happened.
Terrain Offers 'Good Concealment' But At A Risk
Miles before the only U.S. Border Patrol checkpoint in Brooks County, located in Falfurrias, Texas, undocumented immigrants are often dropped off by smugglers and left to circumvent authorities by cutting through private ranches, knee-deep sand and thick brush.
"The constant walking and the vegetation being the way it is, it's good for concealment and hard to extract them," said Chief Deputy Benny Martinez of the Brooks County Sheriff's Office.
The biggest indicator of the flow of undocumented immigrants into the United States, the number of apprehensions at the Mexican border, has steadily declined, with 356,873 cases reported in 2012, compared with 1,649,884 in 2000.
Despite the decrease, there has been a significant uptick in apprehensions at the South Texas border, particularly the Rio Grande Valley border crossing, which reported 97,762 apprehensions in 2012, up from 59,243 in the previous year.
The increase in apprehensions seems to match the increasing number of bodies being recovered in Brooks County.
In 2011, Martinez and his team recovered 129 bodies, and this year he said he expects the death toll to double.
"They're not equipped to [cross]," Martinez said. "They get a story that it's a quick distance, but a gallon of water won't do it."
Lori Baker, a professor of anthropology at Baylor University who is working on a project to identify the dead, said crossing through Brooks County would require the stamina of an Ironman competitor.
"When you walk through a lot of these areas, the sand is up to your knees," she said.
Much of the 943 square miles of Brooks County is sparse, meaning that bodies sometimes aren't found for days or even months.
"Because of the heat and the wildlife out there, they get torn up pretty bad," Martinez said. "Coyotes, wild hogs, badgers. There are a lot of issues like this."
Identifying the Dead
The bodies of more than 100 undocumented immigrants who died crossing through Brooks County sit in two university laboratories in various states of decomposition, some still with soft tissue and ligaments, while others are reduced to bones.
What is known about each set of remains may be minor, such as their gender or the location of where they were recovered, but Baker knows they're not nameless.
"It's a mass disaster," she said. "A lot of them are coming from far south in Mexico and other places in Central America, so by the time they get to the United States, they're exhausted and weary."
In May, Baker and her students, along with a team from the University of Indianapolis, exhumed 63 bodies from paupers' graves at the Sacred Heart Burial Park in Falfurrias, where space is so scarce she said some graves are dug on the side of the road.
Metal placards mark each grave. "Unknown Female," reads one, and below it a serial number, "1193489."
As students with shovels unearthed body bags and pine caskets, they often found more than one set of remains per placard, said Jennifer Husak, 21, a Baylor senior studying forensic anthropology.
"It made it more real, how big of a problem this is, and how many people are dying from trying to cross the border," she said.
Martinez said deputies have processed 31 bodies so far this year, outpacing last year by 90 percent. He said the deaths spike sharply each summer as temperatures heat up, making the harsh terrain even more difficult to navigate. The deputy said he fears this is going to be a particularly lethal summer.
It's also hard on his deputies who have to deal with the unsettling discoveries. He described one call where he found a scalp with hair attached 50 yards from a woman's body.
"We picked that up and brought it back to the body," he said.