Mexican Indians have grown maize, worshipped nature and lived by the light of pine torches in the canyons of the western Sierra Madre mountains for centuries. But this way of life is abruptly changing.
Now armed drug gangs are forcing them to plant opium poppies and marijuana in their ancestral lands, which lie in a notorious region dubbed Mexico's 'Golden Triangle' of drug trafficking.
The rugged point where the states of Chihuahua, Durango and Sinaloa meet is home to around 90,000 Tarahumara, Tepehuan, Pima and Guarijio Indians, around half of whom are getting caught up - only a few of them willingly - in the spiralling trade, community leaders say.
The vulnerable groups live in log cabins or caves hewn from the rock of the plunging mile-deep canyons. Speaking in a consonant-rich dialect, they live by planting maize and beans and raising goats in a precarious hand-to-mouth existence.
Since the 1970s, tribal activists say at least 40 indigenous leaders have been gunned down by the chainsaw-wielding loggers and drug planters, in a conflict that is little known in the rest of Mexico.
The problem has recently become so bad that it is reaching even far-flung villages like Pino Gordo, a highly traditional Tarahumara Indian community watched over by peyote-chewing shamans, some 80 kilometers from the nearest road.
"Outsiders are coming in and cutting down our oak and pine trees without our permission," the community's traditional leader Prudencio Ramos said in broken Spanish.
"They walk among us with guns and sow marijuana and poppies, and people are afraid," he added.
Drugs, guns and chainsaws
While home to indigenous groups, the rugged tri-state area is also the cradle of the Mexican drug trade, where Chinese settlers first came in the 19th century to grow opium poppies for morphine-based painkillers sold in the United States.
Now, locals say traffickers are pushing ever deeper into the labyrinthian canyons of the Sierra, felling the old growth forests and planting illegal drug crops away from the vigilant gaze of the Mexican army, who set up road blocks in the area.
"The traffickers look for the most out-of-the-way places to plant marijuana and poppies ... and these are precisely the areas where the indigenous groups live," said Ramon Castellano, a local agricultural consultant of mixed Pima Indian descent.
They force some Stetson-wearing Indian farmers to plant marijuana and poppies at gun point. Others accept seeds, money and provisions from the traffickers in a bid to squeeze a few extra pesos from their marginal lands.
Toward harvest time in March and April, locals say burly cartel minders with assault rifles and two-way radios watch over the pockets of opium poppy blooms, which are transformed into increasingly pure "black tar" heroin and smuggled over the U.S. border.
"If it's a good year, the farmers can earn more than they can by planting maize," said Isidro Baldenegro, a Tarahumara activist who won a prestigious Goldman Environmental Prize this year for his efforts to protect the forest communities.
"But if the army goes in, then they lose the crop and they don't even have the maize left to eat," he added.
Baldenegro, whose father was killed by an unknown gunman in 1986, has an armed police escort when he travels in the mountainous region after being harassed by powerful and well-connected drug loggers.
He was jailed on false charges of arms and drug possession in 2003, before being released 15 months later following pressure from international organizations including Amnesty International.
Traditions under threat
Mexican drug gangs are growing increasingly violent, and authorities say they have killed more than 1,000 people since the start of 2005 in a war for control of the lucrative trade in cocaine, marijuana, heroin and amphetamines worth billions of dollars in the United States.
The Sierra Madre Alliance, a nonprofit organization which supports threatened indigenous groups in the region, says the cartels' profits and networks of influence are forcing the Indians off their traditional lands.
The fall-out from the trade is also hitting tribal peoples' customs hard, filling traditional villages with guns, cash and consumer goods, while rates of drug and alcohol abuse there are starting to climb.
"There are now Tarahumara youngsters who smoke marijuana, which they never did before, and it's very common for them to get drunk when they have the money," said Baldenegro.
"They also buy loud radios and play music, which annoys people during the traditional festivals," he added.
Locals say some youngsters now play thumping accordion ballads called 'narco-corridos' honoring local drug lords, while others venerate Jesus Malverde - the bandits' patron saint.
As the snarling chainsaws and cartel pistoleros close in on Pino Gordo, regarded as one of the last untouched Tarahumara strongholds in the sierra, Baldenegro is desperate.
"We are calling to the four winds for help," he said. "If we don't get it, there is a real danger that traditional life here will simply disappear."