The police chiefs met in the dusty plaza with a federal official clutching a black bag filled with pesos: $40,000 in government pensions for the senior citizens living in the pueblos of the nearby foothills.
A convoy of seven vehicles rumbled into the plaza, the trucks squeezing between taco and T-shirt vendors who gawked at the 60 or so federal and state police officers toting assault rifles.
The crack squad had captured drug cartel kingpins and battled gangs from Baja California to Michoacan. On this day they slipped on their ski masks to escort the police chiefs on a mission of mercy to a lost corner of Mexico.
They would be heading deep into the scrublands of the Sonora Desert where hundreds of cartel gunmen controlled the pueblos and ambushed intruders on hillside roads that have become blood-spattered shooting galleries.
The convoy was outmanned, outgunned and probably didn't even have the element of surprise. Cartel lookouts — they could be anybody: taxi drivers, store owners, fellow cops — had no doubt already tipped off the organized crime groups. Cellphone conversations were routinely intercepted.
"I'm talking here and the mafia is listening," said one commander who, like many police, residents and officials, spoke on condition of anonymity out of security concern. "They already know we're coming."
The convoy turned past the small church and the local newspaper office, its windows blasted out, and ran every red light and stop sign leaving town.
This is Mexico's hidden drug war.
Ciudad Juarez and other violence-torn urban areas may rack up large body counts and capture headlines and presidential visits. But here in the northern part of the state of Sonora, two of Mexico's strongest drug cartels are waging a battle for scores of human and drug trafficking routes into Arizona that may be just as sinister.
One of the gangs is using a slow, bloodless strategy of patience over confrontation: It's trying to starve out its rivals.
The result is a siege of medieval proportions that has cut off a region about the size of Rhode Island from government services, and severed a lifeline to thousands of ranch hands, storekeepers and retirees. Few dare leaving on the roads, and even fewer brave going in.
"Nobody will guarantee my security," said Juan Alberto Lopez, a consultant who was supposed to drive up into the foothills for meetings with pueblo officials. "They told me they would come down to Altar," he said. "But they haven't shown up."
The war escalated this summer when Beltran-Leyva cartel gunmen took over the string of pueblos and ranch lands stretching 50 miles from Altar to the Arizona border. Their foes in the Sinaloa drug cartel have since surrounded them. They patrol the four main winding roads leading in and out of the hills and block almost all food and gasoline shipments.
There have been massacres and scores of kidnappings, but the war has gone largely unnoticed because of its remoteness, intimidation of journalists and the slow-motion tactics.
"The problem is that one gang is hiding out, very well concealed," said a high-level Sonora state law enforcement official. "And the other group wants to get them out, to restore control over that area."
Caught in the middle are an estimated 5,000 people who every day wake up with questions: Were there any kidnappings overnight? Have the gunmen taken over another ranch? Are there any tortillas in the store?
One grandmother in Saric, grief-stricken over the kidnapping of three sons, said she tried to get help from the mayor, but he hasn't been seen in days.
She's losing hope: "Our town is dying."
Before heading out on its 40-mile journey into the foothills, the convoy took over all the pumps at a Pemex gasoline station. The officers bought sodas and chips, and stuffed them into their bag lunches; food might be scarce along the way.
The police chiefs shook hands with some of the officers. It wasn't clear whether they were greetings or wishes of good luck.
Few reporters have ventured into the area, and public officials refuse to provide much information, fearing retaliation. Since September, two mayors, a police chief and at least 11 officers have fled, joining hundreds, perhaps thousands, of residents who had abandoned the region because of the tightening siege.
Hungry, encircled gunmen have invaded ranches to slaughter cattle. They roam pueblos in large convoys, kidnapping people and tossing their tortured bodies into the road. Many residents stay indoors when night falls, avoiding contact with the Beltran-Leyva gunmen, and stay off the roads for fear of being stopped at highway checkpoints set up by the Sinaloa gang.
"We're living desperate times here. They're not letting supplies through.... We're down to basics, beans and potatoes," said one longtime female resident of Tubutama, a pueblo perched on a mesa and known for its white-washed mission church and plaza, where locals and visiting Americans on mission tours once sipped drinks and listened to bands on summer nights.
The two cartels are warring over Mexico's most valuable region for smuggling people into the United States, with an infrastructure of drivers, guides, suppliers and fleabag hotels that has pumped millions of immigrants across the border. Each cartel has allied itself with local gangs with names like the Wild Boars and the Masked Ones.
In the scorching valley south of the foothills, most residents appear to have sided with the Sinaloa group, saying they at least have brought order to the messy business of smuggling drugs and people across the border.
Cartel toll takers monitor the Altar-Sasabe highway leading toward the frontier, making sure each immigrant-loaded van has paid the $100 fee for each. Rogue gangs that preyed on vulnerable immigrants have been chased out by the cartel, say some residents and immigrant safety groups.
Life in the valley follows a relatively secure, if hyper-vigilant, routine. When a pair of reporters walked through the town of Pitiquito a day before the convoy hit the road, a pack of teenagers and men wielding a club and a baseball bat descended on them.
"Whose side are you on? What are you doing here?" one of them asked.
A middle-aged woman walking with her teenage daughter later explained that the town was controlled by a young Sinaloan crime boss greatly respected by residents. Two of his gunmen had joined hundreds that afternoon in a funeral procession for a popular musician killed in an accident. The crime boss probably paid for the funeral, she said.
"He's the one on our side" of the war, one woman said. "He is a generous man and protects us. Nobody is even allowed to sell drugs here. Everybody loves him here."
In the sparsely populated foothill towns known as the pueblos de arriba, the towns up above, expressing such sentiments can be lethal.
The government force began its steady ascent on the two-lane road and passed through the pueblo of Atil, where many residents avoid using telephones, believing the cartels can listen in.
One former resident, a middle-aged woman, said her son was kidnapped and killed this year, and that the family had to flee with a mattress strapped to their pickup truck. Though she's concerned for family members left behind in Atil, she won't call them.
Her son, she said, was slain execution-style and left on the side of the road.
"We haven't taken sides. We're not with one group or the other," said the woman, who asked that her identity and new home not be disclosed. "That's why I don't understand what happened. There are no answers."
The convoy passed Atil without incident, but as the road ascended further, the landscape began revealing signs of neglect and cartel activity. Vegetation and rocks from landslides encroached on the roadway; signs were defaced and gasoline stations abandoned.
Outside the community of Cerro Prieto, the roadway cut through a hilly area where the war's grisliest massacre occurred.
In July, Beltran-Leyva gunmen took positions above the road where 20-foot embankments provided an ideal ambush overlook; a convoy of Sinaloa gunmen approached. As the cars passed, the gang blockaded both ends of the road and opened fire on their boxed-in enemies. Twenty-one Sinaloa cartel members were killed. Based on the thousands of spent bullet casings, police estimate that there were more than 100 attackers.
New patches of black asphalt cover the blood. The convoy's drivers speeded through the embankments, careful not to bunch up their vehicles and leave them vulnerable to a similar ambush.
Attempts to root out the criminals have been frustrated by the rough terrain and guerrilla-style tactics used by the shadowy force, say federal and state agents. The gunmen strike and then rush back into the gullies and hills dotted with towering saguaro cactuses and mesquite patches.
"When we go up after them, there's nobody there. We can't find them," the high-level Sonora law enforcement official said.
The gangs seem to know everything. The federal police, who wear blue uniforms, overhear the chatter of cartel lookouts on their radios, reporting their positions with unsettling exactitude.
"They say, the blues … are heading your way," one federal police officer said.
"We know they're watching us, but we can't see them."
Turning onto a dirt road, the convoy approached the village of Saric, the deepest point in cartel-held territory.
They planned it so they'd arrive there early, wouldn't be caught after dark in the region considered the hardest-hit by the siege. The day before, people answering phones at the town hall didn't know the whereabouts of Mayor Fidel Lizarraga Celaya, and couldn't say when, or if, their 10 police officers would return.
Dozens of children, women and senior citizens were waiting for the convoy at the town hall. Many of the elderly pushed walkers across dusty streets. Some leaned on their weathered canes or sat in scratched-up wheelchairs. Conspicuously absent were young men. Residents said most had either fled, been killed or joined the cartels.
The federal official toting the black bag strode into the town hall, past the town's lone police car, a battered Nissan with a flat tire whose only apparent purpose was to provide shade for a sleeping, flea-infested dog. As officials began distributing the money — for the first time in four months —citizens gathered outside.
Several elderly women, speaking in hushed tones, said their town was controlled by gunmen who emerge at night and patrol the town in convoys of 20 to 30 vehicles. The gang members, hiding behind masks and tinted windows, stop for any "suspicious activity," such as using a cellphone or carrying food, questioning and in some cases kidnapping residents, they said.
Mail carriers, produce and soda distributors, even ambulances, have stopped going to the town, they said. They pointed to several abandoned homes. A middle-aged grocer looked at the dwindling stock on her shelves, saying two months had passed since her last deliveries. There was no meat or soda, or flour to make tortillas.
The only food supplies were brought in by older, longtime residents who shopped in Altar and were allowed through the cartel checkpoints, apparently trusted by gunmen to not pass along the food to rivals.
The meager supply was distributed among a close-knit circle of older, relatively well-off residents, said one woman. A few pesos could buy some food, toilet paper and medicine, but not much.
"I don't know what the poor people are doing for food," she said.
Seeing the federal police posted around the perimeter of the town hall emboldened the despairing Saric grandmother. She barged into the one-room police station and demanded that the authorities investigate the kidnappings of her sons.
A top police official, speaking privately later, made it clear that no investigation was likely. "I don't arrest any of them. That's how I stay alive."
Back in the town hall, the crowd parted for the arrival of the town's oldest resident. Manuel Aureliano, 100, was wheeled into a cramped office, where he presented his I.D. and was given a stack of 500-peso notes, for a total of about $450.
The great-great-grandfather clutched one 500-peso bill in his hand, kissed it and raised it over his head. Born during the Mexican Revolution, the deaf man celebrated the arrival of the government force like another national triumph, instead of a rare, small victory against the cartels.
"Gracias a Dios!" he yelled. "Viva Mexico!"