Sasabe, Arizona — Migrants from all corners of the globe come here to cross into the U.S. through breaches or gaps in the border wall, which covers miles of a rugged landscape featuring steep hillsides, dirt roads, cows, cacti and desert shrubs.

While the towering Trump-era wall is by far the most visible man-made object, if visitors venture far enough into this section of the U.S. southern border, they will also see construction crews fixing parts of the wall damaged by erosion or smugglers, clothes, blankets and other belongings abandoned by migrants — and water stations maintained by volunteers hoping to prevent tragedies in the unforgiving desert.

The nearest U.S. community, Sasabe, is a hamlet with 51 residents, according to the Census Bureau. It has an official port of entry to facilitate legal travel from and to Mexico, several modest residences, a post office and a store that sells burritos, cowboy hats and souvenirs, including t-shirts that pose a question many newcomers may ask themselves: “Where the hell is Sasabe?” 

Nestled between the Tohono O’odham Nation Reservation and a highway that connects Tucson with Nogales, Mexico, this area in southern Arizona is one of the most remote stretches of the U.S.-Mexico border. For the past months, it has also been the busiest region for Border Patrol apprehensions of migrants entering the U.S. unlawfully.

Undeterred by miles of border wall, violent Mexican cartels and a treacherous terrain with extreme temperatures, migrants have been crossing into the Tucson sector of Arizona by the hundreds, and sometimes by the thousands, each day — often with the help of smugglers. 

During the first four months of fiscal year 2024, Border Patrol recorded more than 250,000 migrant apprehensions in the Tucson sector, the most of any region patrolled by the agency, according to federal government statistics. While illegal crossings into Texas are down from last year, they have remained high in the Tucson and San Diego sectors, which have been recording 60% of all migrant apprehensions.

There are two types of migrants crossing into the Tucson sector illegally: those surrendering themselves to Border Patrol agents, sometimes with the intention of seeking U.S. asylum, and those hoping to enter the country surreptitiously, without being apprehended.

Due to the area’s remoteness, the first group often has to wait and walk for hours after entering the U.S. before reaching Border Patrol agents. In those cases, the work of American volunteers can be a lifeline. 

On a recent day, volunteers provided basic medical attention to a migrant from Ecuador who said she had been grazed by a bullet before crossing into the U.S. that morning. Maria said armed men she believes were cartel members shot at the vehicle that was transporting her and other migrants to the U.S. border.

“I was bleeding a lot,” Maria said in Spanish, adding that she was so scared at the moment, that she did not feel any pain. “The terrible pain came later.”

In addition to medical attention, Maria received water and food at a migrant camp that American volunteers have set up more than a dozen miles east of Sasabe. The encampment includes tents for migrants to rest, a makeshift kitchen where volunteers cook ramen soup, and a pantry with water, peanut butter, refried beans, canned sausages, tuna and other foods. The site also has blankets, since the temperatures drop sharply at night and in the early morning hours.

Volunteers said the camp is designed to be a barebones respite center for tired migrants awaiting Border Patrol agents. But they said some migrants have had to spend the night there. 

Oftentimes, migrants just want to see a friendly face, volunteers said.

“They fall into your arms and cry and hug you. They go, ‘thank God, we’re in America. We’re safe now,'” said Gail Kocourek, a volunteer with Tucson Samaritans, one of the U.S.-based groups assisting migrants near Sasabe.

While all of the migrants who were at the camp with Maria hailed from Latin America, others from more far-flung countries also cross into the U.S. in this area. Kocourek said she has recently met migrants from Afghanistan, Egypt, Eritreia, Guinea, Liberia, the Palestinian territories and Senegal.

Critics have argued groups helping migrants are facilitating illegal immigration by offering free services to those who entered the country without authorization. Kocourek rejected that accusation.

“We’re not facilitating. We’re just helping people stay alive,” she added.

Erin Waters, a spokeswoman for Customs and Border Protection, said the agency had “redirected manpower” in southern Arizona to process the increasing number of migrants seeking to turn themselves into U.S. officials. 

“Callous smugglers continue to push large groups of vulnerable migrants across the border during winter snow and rain conditions, through some of the most isolated locations along the southern border without proper clothing, supplies, or shelter,” Waters said. “Once aware of an entry, the Border Patrol prioritizes the humanitarian response to the migrants abandoned in the cold.”

Maria said she journeyed to the U.S. due to deteriorating economic and security conditions in Ecuador, which has experienced a surge in violence attributed to drug trafficking cartels. She said she also wanted to reunite with her husband and children in Wisconsin. She said she has not seen them in five years.

“Being without my family makes me feel very sad,” Maria said, before breaking down in tears.

After a few hours at the camp, Maria and the other migrants there were picked up by Border Patrol agents. They were transported in vans to a nearby processing facility, where Border Patrol screens migrants for security concerns before deciding whether to deport them, transfer them to another agency or release them with a court notice. It’s unclear how Maria was processed.

Camilo Montoya-Galvez

Camilo Montoya-Galvez is the immigration reporter at CBS News. Based in Washington, he covers immigration policy and politics.