When the US ramped up security after 9/11 the town became a hub for remoter desert routes. Then la mafia moved in, bringing kidnapping, extortion and death

The migrants who pass through this desert outpost seek invisibility even before they begin the great trek north. After dusk they flit around the stores lining the plaza to stock up on camouflage backpacks, black water bottles and special slippers to cover their tracks in the Sonora desert. Then they vanish down side streets, heads down, avoiding eye contact.

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It makes no difference. There is no escaping scrutiny. The old man on a bench half-reading his paper, the teenagers on bicycles, the men with sunglasses in parked SUVs, all silent, all watching.

Altar, a dusty, sun-baked town near Mexico’s border with Arizona, is a staging post for those seeking to enter the United States illegally, a wilderness Walmart offering guides, transport and supplies ranging from boots to snake bite kits.

It has been dubbed a migrant “oasis”. Times change. These days it feels more like a trap.

Organized crime groups routinely extort, kidnap and kill migrants, turning the town and surrounding desert into a high-stakes gamble. One roll of the dice gets you into the US. Another leaves your bones bleaching in the sand.

“They took my shoes and my phone, left me out there with nothing. I thought, man, I’m dead,” said one migrant, “Miguel”, who asked not to use his real name. Desperate to rejoin his family in California, from where he had been deported, but with no money to pay smugglers, he accepted a Faustian bargain: haul drugs on a moonlit desert trek in return for $1,500 and entry to the US.

“The pack was so heavy I could barely carry it. Then I sprained my ankle. So they took the pack and ordered me to cross back into Mexico,” said Miguel, back in Altar, limping and blistered. “I don’t feel safe here. I’m just prey for them.”

He felt lucky to escape with his life. Gunmen recently ambushed a group of Central American migrants on a border trail, killing three, including two men found in a charred vehicle.

Two rival factions of the Sinaloa cartel known as Los Memos and Los Salazar are waging a murderous war for control, leaving dozens dead this year in and around the town of Sonoyta, down the highway from Altar. Grisly photographs in the local press show their latest innovation: dynamiting captives.

Drug trafficking entwines human trafficking here like desert mistletoe around mesquite trees, a remorseless, asphyxiating parasite. “La mafia”, as it is called locally, controls a web of hustlers, transporters, flophouses, guides, lookouts, enforcers and informants. They are widely perceived to have infiltrated police and government agencies.

Facebook Twitter Pinterest Father Prisciliano Peraza, a Catholic priest and migrant advocate, in front of Altar’s church. Photograph: Rory Carroll/The Guardian

“You pay them or they kill you,” said Prisciliano Peraza, Altar’s priest and an outspoken migrant advocate. “The routes and prices change but the mafia endures.”

The airless heat and the single road in and out of town adds to the sense of cloying menace. Instead of camping out in the plaza and shopping around for guides, as did their predecessors, migrants lie low hoping to minimise contact with predators, including the authorities, who are waging a crackdown on US-bound migrants from Guatemala, Honduras and El Salvador.

“You can’t trust anyone,” said Carlos Velásquez, 37, slumped in a chair at a Catholic church-run migrant shelter. He and three other Mexican would-be border crossers had just arrived, filthy, sunburned, thirsty and exhausted. Their guide had abandoned them in the desert two days earlier, leaving them wandering in circles. Someone – a lookout, they assumed – observed from a distance but did not approach. Eventually they found a road and a lift back to Altar.

“People warned us about this place,” said Velásquez. They risked it anyway, each agreeing to pay a 5,000-peso ($320) tax to the mafia plus $3,000 to be taken to Phoenix, Arizona. Foreigners pay double.

Facebook Twitter Pinterest Carlos Velásquez, a Mexican migrant, rehydrates at a church-run shelter in Altar, Mexico, after returning from the desert. Photograph: Rory Carroll/The Guardian

Manuel Cruz, 29, lips chapped, eyes glassy and so worn out he dozed off twice during the interview, said his family borrowed the cash so he could join relatives working in restaurants in Los Angeles. Three months ago his wife gave birth to their first child, a girl. “I want to support them,” said Cruz.

The group felt marooned in Altar, unwilling to trust police, bus drivers or government officials lest they feed information to the mafia. “It’s a game of mice. Running and hiding,” said Velásquez. “To advance we need to trust someone. But who?”

It was not always like this. In the 1980s and early 1990s local smugglers known as coyotes would lead groups through the thinly guarded border around Mexicali, Nogales and other urban centres, making small detours into wilderness.

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When the US ramped up border security after 9/11, coyotes switched to remoter routes through the desert, turning Altar, 60 miles from Arizona, into a major migrant hub. By 2007 several thousand reportedly passed through daily, a human wave which transformed the sleepy agricultural town.

Instead of tilling fields of cucumber, melon and asparagus locals catered to the influx with minivans, hotels, flophouses, packed lunches and hiking supplies. The mafia promptly muscled in, demanding a cut.

“The plaza was packed. At night people slept on the pavement, the road, everywhere. You wouldn’t believe how busy it was,” Alfredo Triana, 65, a store-owner, recalled fondly. In addition to camouflage gear and black water bottles (to avoid reflecting sunlight) he sold water tablets and electrolyte as well as combs, razors and deodorant – grooming kits to avoid attention upon arrival in US cities. Pharmacies also sold birth control kits to female migrants who feared rape.

But business has evaporated, Triana sighed. He gestured to the near-empty plaza. “Look. Nobody.” Nearby flophouses with optimistic names like Hotel Arizona and House of Dreams were quiet.

Facebook Twitter Pinterest Camouflage clothing, caps and supposedly footprint-erasing slippers on sale in Altar. Photograph: Rory Carroll/The Guardian

The number of migrants has plunged, halting construction of new businesses and forcing many hostels and shops to close, said Adrián Caldera, an official with Integral Family Development, a government agency. “It’s a recession.”

Apprehensions by US border authorities – an indicator of overall border crossings – exceeded 1 million in 2006, after which numbers dropped to 340,252 by 2011, a dramatic fall attributed to the US recession and massively expanded border security, which now includes 4,000 border patrol agents in the Tucson sector alone.

Apprehensions have begun to climb again, to 486,651 last year, but it remains unclear how much Altar will profit from any rebound in migration.

Townspeople confide that the mafia has become too greedy, ratcheting up prices and violence and breaking too many “eggs” – a euphemism for migrants. “Word gets out,” said one local government official, shaking his head. “It’s ‘watch out, don’t come here.’”

But if not here, where? The mafia is entrenched along the 2,000-mile border. And US border security whittles down options to desolate, perilous areas such as the Sonora desert.

Additionally, years of record deportations under the Obama administration have created a generation of hyper-motivated border crossers who will run seemingly any risk to rejoin families in the US.

Facebook Twitter Pinterest Byron Pineda. Photograph: Rory Carroll/The Guardian

Byron Pineda, 40, a tow-trucker who spent 28 years in the US, speaks English like a gringo and has a wife and two teenage children waiting for him back in Los Angeles.

The account of his odyssey from Guatemala through Mexico included rafting across one river, wading across another, hiking over mountains to evade police patrols, collapsing from hunger, witnessing the rape of a female Honduran migrant, losing a friend from a moving train, being stabbed by a mugger, joining a circus and finally ending up in Altar, alone and broke, not knowing how or when or where he will cross the border, just that somehow, some day, he must. “My life is over there. I want to see my kids.”

On Thursday in our series on America’s refugee crisis: Fewer people cross the Arizona desert – but more of them die