Mennonites are descended from 16th-century Swiss Anabaptists. The conservative sect of Mennonites that eventually settled in Mexico first scattered throughout Europe, then Russia, then Canada, moving frequently to escape religious persecution and searching for places where its members could opt out of military service (they are pacifists) and educate their children in their own schools.

Mennonite immigrants first arrived in Chihuahua in 1922, where they found a tolerant government. They purchased about 250,000 acres of land in Cuauhtémoc, in central Chihuahua, now considered the Mexican Mennonite heartland. Today, about 80,000 Mennonites live in Mexico, with most in Chihuahua, and own some 865,000 acres of land.

At first, they eschewed modern technology, farming with rainwater and traveling by horse and buggy. But in the 1950s, one of the first known Mennonite irrigation systems arrived in Cuauhtémoc, when a farmer installed a center pivot sprinkler on his apple orchards. Each center pivot is capable of watering about a quarter of a square mile, so more Mennonites followed suit. While adoption was initially slow -- due both to internal resistance and the steep cost of sinking wells and installing center pivots -- the practice escalated in the early 1990s when a savage drought hit the region. Irrigating fields with groundwater became the surest way of making it as a farmer. Grassland conversions soared.

In 2005, when Pedro Calderon was a 20-something bird biologist for the Mexican conservation group Profauna, he witnessed the arrival of industrial agriculture in Valles Centrales. Mennonites purchased over 20,000 acres of ranchlands, then showed up at Profauna's office, explaining that Mexico's environmental police, Profepa, had fined them for clearing the land without contracting for and completing an environmental review to obtain the requisite land-use change permit. To clear lands, a developer must pay SEMARNAT, Mexico's equivalent of the U.S. Environmental Protection Agency, about $230 per acre. The penalty for clearing land without a permit can total hundreds of thousands of dollars.

The Mennonites wanted to know if Profauna could help bring them into compliance with Mexico's environmental laws. When Calderon visited the ranch to investigate, he almost cried. Stretching as far as he could see was nothing but deep brown soil. Profauna returned the farmers' money and began urging officials to take heed. "We started writing letters. We tried to talk to the president of Mexico and we talked with the governor of Chihuahua. We did everything to try to inform people about the problem, but the government never listened to us," Calderon says.

So sodbusting continued, vastly in excess of what the government actually issued permits for, according to Alberto Macías Duarte, a wildlife ecologist at Sonora State University, who has been compiling permit data from Valles Centrales.

Many farmers forgo permits because they know that even if they get caught, they can keep clearing land, says Profauna Director Alberto Lafon. If the parcel of land is large enough, the penalty can be cheaper than the clearing fee. Many in the conservation community say that farmers also obtain permits through bribes.

Because most Mennonites in Mexico are educated in low German and finish school around age 12, many cannot read Spanish and may not realize that they aren't going through proper channels, says Marion Meyer, who heads the Mexican office of the Mennonite Central Committee, a global Mennonite outreach organization. Even when they know the process is a farce, Mennonites often feel they have no choice but to pay under the table. "Some of the things we've heard from Mennonites are like, 'You want to go the legal route. And then you request a permit and … you're sitting there waiting six years for your permit.' " SEMARNAT subdelegate Gustavo Hereda declined to comment on allegations of corruption. "It's hard to get the permit because we study each case individually," he says.

Pablo Dominguez, a SEMARNAT official I met at El Uno, told me the agency is too short-staffed to protect such a large area. And because officials can't block ranchers from selling to farmers, they are perpetually behind the action once clearings start. Dominguez recalled an incident where farmers near Janos cleared grasslands containing endangered prairie dog habitat. It was too late to do anything, he says, "so we fined them and let them continue."

Meanwhile, thanks to drought, intensive grazing and industrial farming, the region is rapidly running out of water. Mexico's national water commission, ConAgua, recently calculated that groundwater is being pumped from the Janos region faster than it can recharge.

Juan Harms, an overall-clad bear of a man whose front teeth are lined with silver, is hoping to expand his 130-acre sorghum, pepper, oat and wheat farm in Buenos Aires, a Mennonite community near Janos. But the four wells he's drilled have come up dry; each cost $15,000. Harms is surprisingly unruffled. "I hope for better luck next time," he says in Spanish, through a translator. When asked what Buenos Aires residents will do if the water dries up, he simply says that the resources "can't run out." It's not hard to see why he feels that way: When you look past his fields and John Deere tractors gleaming in the sun, out across the prairie at the confluence of sky and the Sierra Madre, the earth here does feel boundless.