Deep in the Maya Biosphere Reserve in Guatemala, armed men near a stopped white truck face us—one gripping a shotgun, another slashing a nearby branch with a machete. They glare at us menacingly as we drive by. “That was a perfect place to kill someone,” half jokes our guide, Javier.

“Let’s not talk about that right now,” curtly replies Seth Factor, Guatemala director of the environmental advocacy group Trópico Verde. Bands of armed outlaws are a common threat in the western third of the Maya Biosphere Reserve—“the Wild West,” as one scientist here has called it.

The reserve is the heart of the biggest intact forest in the Americas north of the Amazon—at 2.1 million hectares, it is roughly twice the size of Jamaica and covers nearly a fifth of Guatemala. In terms of biology, it is one of the richest forests in the world, boasting at least 100 mammal species, 400 bird species and 3,000 plant species. And it is also home to the epicenter of the ancient Maya civilization, holding the largest excavated Maya city, Tikal.

Fieldwork in this steaming-hot forest has always been challenging; scientists must brave venomous snakes, flesh-burrowing botflies and repeated bouts of malaria. But in the past decade the risks have escalated as criminal activity has invaded the reserve’s western region. Cocaine smugglers have burned tracts of forest to set up dozens of airstrips as way stations from the coca fields of Colombia to dealers in the U.S. Illegal squatters armed with assault rifles have kidnapped scientists and local officials. Poachers and loggers have beaten and shot police, soldiers and park rangers. Nearly everyone I approach is wary of speaking with me because of very real fears of political repercussions or criminal retaliation.

Efforts to drive back these outlaws are underfunded. “We are trying to control 20 percent of the country with less than 0.5 percent of Guatemala’s national budget,” explains Victor Hugo Ramos of Guatemala’s national park service. The country’s booming population may also speed the invasion of the forest—in Petén, the northern third of the country where the reserve lies, official estimates state that the population exploded from 25,000 in 1960 to 500,000 in 2004. The current numbers might actually approach one million, says Roan McNab, the program director in Guatemala for the Wildlife Conservation Society (WCS).

As we drove into Laguna del Tigre, the largest of the five national parks in the
reserve, illegal ranches lined each side of the road. Although I could see the scorched forest attempting to recover from all the burning, the repeated use of fire has worn it down. Squatters have been selling land in Laguna del Tigre, even though they do not own it. “They are betting the government will let them stay there,” Ramos says.

The scientists are now struggling to keep invaders from spreading eastward by patrolling a 45-kilometer-long firebreak between the ancient Maya sites of La Corona and El Perú-Waka’ with the aid of Guatemalan authorities, a strategy that McNab dubs “the shield.” “We’ve been able to hold the shield for the past five years under massive pressure from the invaders,” he says. Volunteer pilots also run flights for the WCS to pinpoint fires and airstrips, and scientists relay that data to law enforcement.

There are more signs of hope from Guatemala’s new administration. The country’s president is taking an active interest in the area, and the park service has begun evicting squatters from the reserve, Factor explains. “But it’s key not to focus on the impoverished communities that are driven by necessity—it’s vital to target the large landholders.”

As I interview McNab in his office in Flores, the capital of Petén, he is preparing to enter the field unarmed in spite of the danger, as he always does. He explains that he has managed to talk his way out of risky situations so far, and by going in armed, he could be seen as a threat. In the end, he adds, “I would rather die with binoculars in my hand than carry around a gun for the rest of my life.”

He returned safe eight days later.

Note: This article was originally printed with the title, "Danger in the Forest".