BROWNSVILLE, Tex. — Elizabeth Lopez swam across the Rio Grande 19 years ago to come to America, where she began cleaning houses and raising three daughters in this city of swaying palm trees at the southern tip of Texas.
It did not matter to her that her life was confined to a narrow sliver of the country — a zone north of the Mexican border but south of traffic checkpoints that the Border Patrol operates within Texas. Everything changed in 2010 when her fourth child, Angel, was born with Down syndrome and colon and heart problems. Living in what some call “la jaula de oro” — the golden cage — suddenly took on a whole new meaning.
For decades, these interior checkpoints up to 100 miles north of the border have left thousands of undocumented immigrants and their families in the Rio Grande Valley in something of a twilight zone. Their isolation has only intensified as border security has tightened. And though neither side of the debate about immigration has focused on the issue so far, that may be changing.
Those stuck here have little choice but to stay put. They cannot go north for fear of either being caught while trying to cross the checkpoints by car or dying in the vast expanses of brush while trying to walk around them. And they will not go south for the same reasons they left Mexico in the first place.
The economic opportunities here are better for the immigrants and their children, many of them American citizens, and some fled threats of violence.
The inability to travel north complicates their lives in myriad ways. For Ms. Lopez and Angel, it hinders medical care. Immigrants here have also missed relatives’ funerals, refused to evacuate as hurricanes approached, narrowed searches for jobs — all because they feared venturing beyond the checkpoints.
Ms. Lopez, who asked to be identified by her middle name and last name, wants Angel, now 5, to undergo surgery beyond the checkpoints, with specialists in Corpus Christi. Angel could easily pass through — he was born in Brownsville and is a United States citizen — but Ms. Lopez cannot because she is an undocumented immigrant and has already been deported once. A single mother, she has no relatives who could take Angel for her.
“If it weren’t there,” Ms. Lopez, 41, said recently of the line of checkpoints, “he would be better already.” Angel had stayed home from school that day because of one of the bouts of diarrhea he endures every few weeks.
Border Patrol officials say the checkpoints prevent immigrants who crossed the border illegally and smugglers from entering the interior of the United States.
In some ways, the immigrants here are facing constraints they should have expected. They came to the country illegally and must now try to live undetected in a region with a heavy Border Patrol presence. But their isolation is extraordinary compared with that of other immigrants who violated the same laws.
Erasto Renteria’s parents will miss his graduation in 2017 from the University of Texas at Austin, although they live in San Benito, near the border and only a five-hour drive away. His parents are undocumented, and they would have to cross the checkpoints if they traveled north.
“As it gets closer and closer, it makes me think whether I actually want to graduate on time, because it’s really hard for me to say that I would graduate without my parents,” Mr. Renteria, 20, said.
Adela Menchaca’s world spans a mere two counties. Since entering the United States illegally in 1999, Ms. Menchaca, 44, who lives in Edinburg, has never traveled more than about 25 miles north, 20 miles west or 80 miles east. Her daughter Roxana moved to Austin after graduating from college in May, but Ms. Menchaca has not visited. Her mother died in Mexico in 2001, but she did not attend the funeral.
At first glance, there is nothing suffocating about Ms. Menchaca’s life in Edinburg. Roosters crow beneath the papaya trees outside the trailer her husband converted into a house. They raised four children — Ms. Menchaca cleaning houses and selling tamales and Avon products, and her husband working in construction.
But she once tried to convince her husband, who trekked on foot around an interior checkpoint in the 1990s, that they should try to make that journey together. Her husband, who ran out of water in the South Texas brush and drank from a watering hole used by cattle, said it was not worth the risk.
“It’s such a helplessness that you can’t leave,” said Ms. Menchaca, who was part of a social-media campaign by United We Dream, a national network of young immigrants. A picture of Ms. Menchaca and her description of being “trapped in the Rio Grande Valley” was shared on Facebook and Twitter.
According to the Migration Policy Institute in Washington, about 130,000 undocumented immigrants live in two of the Rio Grande Valley’s four counties. And experts said they and thousands in the two other counties limited their movements because of the checkpoints. Some successfully cross them, but others fail, and still others never risk it.
The situation is not unique to the Rio Grande Valley. The Border Patrol operates more than 30 permanent checkpoints in Texas, New Mexico, Arizona and California. Immigrant-rights advocates said undocumented immigrants who live below the checkpoints in other states were often similarly isolated.
“It’s pretty common along the whole border area,” said Vicki B. Gaubeca, the director of the American Civil Liberties Union of New Mexico Regional Center for Border Rights in Las Cruces.
One of the checkpoints in the Rio Grande Valley sector is 70 miles north of the border, near the town of Falfurrias, and it apprehends the largest number of people who have entered the country illegally — 14,243 from October 2014 to August.
Border Patrol officials make no apologies for the hardships experienced by undocumented immigrants restricted by the checkpoints, but they say families with serious medical needs can use short-term visas or so-called humanitarian parole to travel beyond them. Officials said the agency made sure people had access to emergency medical care.
“Without the checkpoints, then you have narcotics and people just coming straight up the highways,” said Raul L. Ortiz, the acting chief of the Border Patrol’s Rio Grande Valley sector. “I think we bend over backwards as an organization to help people in need.”
In this part of South Texas, there are only two major highways leading north from the border, and each has a checkpoint, in Falfurrias and in Sarita. Those checkpoints are surrounded by ranches, detection sensors and rough terrain. Officials in Brooks County, where the Falfurrias checkpoint is, said the bodies of 459 people had been found since 2009. Advocates think all were immigrants who died of heat and exhaustion while trying to walk around the checkpoint.
George Rodriguez, a conservative activist in San Antonio, disputed the notion that undocumented immigrants were trapped. “The law says if you enter the country illegally, there’s consequences,” he said. “The way to resolve this issue is simple. You come in legally, and then you don’t face the complications.”
Few in the Rio Grande Valley are as limited by the checkpoints as Angel and other seriously ill or disabled children who were born in Texas to undocumented parents and have American citizenship. The specialized care they need is often available only north of the checkpoints, doctors and immigration lawyers say.
Dr. Marsha Griffin, a Brownsville pediatrician, said a child who had died en route to Corpus Christi did not have his parents by his side because they were undocumented and feared crossing a checkpoint.
Dr. David A. Yngve, the chief of pediatric orthopedics at the University of Texas Medical Branch at Galveston, regularly travels to the Rio Grande Valley. He said there were children with cerebral palsy and other disabilities who “are not walking as well as they could because they can’t make it past the checkpoint.”
Dr. Carmen Rocco, who treats Angel, said it was unclear how much surgery would help him. But she said that if Ms. Lopez had easy access to a city with a children’s medical center, Angel would be in better health.
Ms. Lopez said she had left the valley only once since 1996 because of the checkpoints — a harrowing trip five years ago. Angel was 4 months old and needed emergency heart surgery. Ms. Lopez said that she had flown over the checkpoints on a medical helicopter with Angel to a San Antonio hospital, and that she had been terrified not only that Angel might die but also that she might be deported again.
The helicopter landed in San Antonio, and she saw a group of people walk toward her, she said. They were wearing green uniforms — the same color worn by Border Patrol agents — and she thought she was caught.
But it was a kind of mirage, brought on by years of fearing the checkpoints. The people were not with the Border Patrol. They were uniformed paramedics.