MEXICO CITY, Mexico — Some locals call the long, arid valley Tierra Caliente, or the Hot Land. To others it’s Infiernillo, which means Little Hell.

Such colorful nicknames refer to more than just the scorching climate: the Hot Land is also the newest front line in the Mexican Drug War.

Running through southwestern Guerrero state, where 43 students disappeared in September of 2014, the infernal vale encompasses some of the deadliest country in the hemisphere.

While other major cartel umbrella groups—like Chapo Guzmán’s Sinaloa cartel federation—have been weakened by loss of leadership and infighting over the last year, intelligence reports show dozens of drug trafficking organizations (DTOs) in Tierra Caliente growing stronger in 2016.

And with good reason. Tierra Caliente has already eclipsed Mexico’s famous “Golden Triangle” as the prime heroin production zone, with most of the smack headed straight for the booming U.S. market.

All that heroin-derived revenue allows the Hot Land’s cartels to prey, vampire-like, on the region’s farmers, business owners, and politicians. The gangs’ preferred terror tactics include kidnapping, extortion, rape, murder, and even organ trafficking.

In just the last three months, there have been more than 340 murders in Tierra Caliente and neighboring municipalities. In January alone, authorities recorded at least 35 “forced disappearances,” including several children, causing schools to close throughout the region.

In addition to targeting civilians, local gangs also engage in bloody, shockingly brutal turf wars. As the narcos duke it out over local drug-production plazas, innocent civilians are often caught up in the chaos.

“There’s a human-rights crisis in Tierra Caliente, and it’s not being attended to,” says Laura Carlsen, director of the Mexico City-based Americas Program, in an interview with The Daily Beast.

“I’ve been in Mexico for 30 years,” Carlsen says, “But I never imagined that we could see the levels of violence happening now.”

The rugged mountain ranges on either side of Tierra Caliente tend to soak up most of the rainfall, leading to the desert-like conditions in the valley below. The nearby high country also provides excellent cover for the mass production of opium and heroin, as well as crystal meth.

Unlike local rainfall, illicit drugs do flow all the way downhill into the Hot Land, as traffickers prefer to move their product out along the flat, paved valley roads. Conflict over these shipping routes can be fierce. According to Carlsen, whole villages have been displaced, as the regional mafias struggle for dominance.

These new gangs have names like Los Rojos (The Reds), Guerreros Unidos (Warrior’s United) and the Jalisco New Generation Cartel. And those upstart DTOs have a different, far more violent ethos than the old cartel vanguard, which was personified by Chapo Guzmán.

One disturbingly common tactic in Tierra Caliente is skinning off victims’ faces while they’re still alive. Other go-to moves out of the cartel playbook include using chain saws and other power tools as torture devices, ISIS-style beheadings, and dissolving people in vats of acid.

Many experts believe the increased violence in places like Tierra Caliente is indicative of the failure of the DEA-sponsored “Kingpin Strategy,” which emphasizes hunting down high-ranking cartel leaders, as opposed to stressing interdiction efforts.

Once a given crime lord is taken down, critics say, it almost always touches off a battle among his seconds and lieutenants, as they seek to take over and gain power for themselves.

“When a cartel divides and forms new groups—well, those new groups need to find sources of income,” says Mayra Jiménez, an independent Mexican journalist who has covered the Tierra Caliente region for more than a decade. “That drives them to take over new plazas, and to extort and kidnap people in them.”

For example, some of the most powerful cartels in Guerrero—including the Rojos and the Guerreros Unidos—are splinters of the Beltran-Leyva organization, which the Mexican government took down in 2011.

Competition among such factions has led directly to the new, no-holds-barred tactics.

Turf wars have become more violent, as each group seeks to send a message about “who’s the toughest dog on the block,” says America’s Program Director Carlsen, who just returned from a research trip to Tierra Caliente.

All those dog fights have taken a drastic toll on the quality of every-day life.

“Cartel activity really restricts freedom of movement,” says reporter Jiménez. “People know they can’t be out on the street after 6 or 7 at night. And even during the day, the roads aren’t safe.”

Meanwhile, the cartels are suppressing freedom of the press.

“We can’t even write about what the narcos are doing without putting ourselves at risk,” says Jiménez, who also lives in the Tierra Caliente. “If you say something they don’t like, they’ll hunt you down and kill you. Or they’ll hunt down your family.”

As with so many places in Mexico, authorities seem helpless to curb the violence. A major government offensive in 2014 established a powerful police and military presence in this little inferno, complete with scores of stop-and-search checkpoints. But the number of killings, abductions, and other crimes has actually surged during the occupation—as has drug production.

“A real question is raised here,” says Carlsen. “If the federal government is in charge—why is the violence [in Tierra Caliente] on the rise?”

Carlsen hints at a dark, “deductive” answer to her own question: that federal forces in the area are “complicit with the cartels.”

“All access roads are controlled by the military, yet there’s still a huge flow of drugs,” says Carlsen.

“The responsibility of the state to guarantee human rights and security—is simply not being met,” she says.