Every year, an untold number of migrants attempt to cross the U.S. southern border without government authorization. The flow of humanity is persistent and undeterred. Even with the threat of imprisonment or death they still come.

Getting past the Rio Grande is not the only challenge. The harsh South Texas desert is also an unforgiving obstacle. The region is literally littered with the remains of people who didn’t survive the trip.

“Brooks County 911 – hello?”

From the sweltering desert comes a call for help.

It’s common for the Brooks County sheriff to receive 911 calls from migrants who are lost in the harsh terrain and are near death.

This time a group of migrants from El Salvador who have been beaten down by the heat, dehydration and exhaustion are giving up on their dream to immigrate to the United States. They want the Border Patrol to come and get them.

But where are they in all that scrub brush acreage? They don’t know.

Credit David Martin Davies | Texas Public Radio Jugs collected for thirsty migrants.

They look for clues, and the 911 operator tells them help is coming but it’s going to be a while. As the call ends the woman in the desert expresses that she's lost all hope and expects to die there.

Brooks County is about 70 miles north of the border with Mexico. This is where the Border Patrol strategically stationed a checkpoint on Highway 281 at the town of Falfurrias. For migrants looking to enter the interior of the U.S. they know that they must to avoid the checkpoint to evade capture. They travel on foot into the Thorn Brush Desert.

“It could be as far south as 50 miles away or could be real close to the checkpoint. In this heat in this weather it gets pretty serious,” said Eddie Canales, who works for the South Texas Human Rights Center.

“They're crossing through thicket. A thick brush, mesquite, cactus, everything that can ... imagine that has a thorn in it. And then underneath is sand. This is kind of like what they're referred to as the coastal grassland. So it's like a beach, and ... walking through sand is difficult,” he explained.

Credit David Martin Davies | Texas Public Radio Eddie Canales puts a water station at the Brooks-Duval County Line.

It’s so difficult that many die. In 2019, more than 30 sets of human remains were discovered in Brooks County alone. That number is down from previous years. Over the last ten years it’s estimated that 700 people died crossing Brooks County. The remains of most of those people were never recovered. Their bodies are left where their coyote guides left them.

“At the King Ranch, a lot of recovery here," Canales said. "These three main ranches -- that’s where bodies are recovered and skeletal remains.”

In the summer, the temperature is routinely over 100 degrees. And it’s during the summer that Brooks County sees the most migrants. Canales’s mission is to help the people who make that journey come out of the desert alive.

“We've got over 170 water stations. You’re trying to get water in between, water before and water after. But we’ll never have enough.”

Canales recently spent a day building a few more stations. He also checked on others to see if they needed to be restocked with water jugs.

Each water station consists of a big blue plastic barrel with the word “agua” painted on the side. Inside there are gallon jugs of water sitting on a crate.

Credit David Martin Davies | Texas Public Radio GPS coordinates are painted on the barrels in case the migrants need help from authorities.

“The crates are there to make it easier for people to pick up the water,” Canales said.

He said he rarely sees any of his water stations vandalized. Rather, he has seen that people in nearby communities have added fresh water jugs to the stations.

“If you see people dropping a case of water into your water station -- there is good faith,” he said.

On top of the station, there’s a tall pole with a white flag that’s whipped back and forth in the desert wind. On the lid of each of the barrels there the GPS coordinates for that location.

So if a group of migrants needs help, they can tell authorities exactly where they are. And the Border Patrol can pull them out of the desert while they are still alive.

David Martin Davies can be reached at DMDavies@TPR.org and on Twitter at @DavidMartinDavi.