BOLD FARMING: Pesticide used at a marijuana grow site in Sequoia National Park in California is prepared for removal by helicopter. (Photo: Gary Kazanjian/AP)
Not far from Yosemite's waterfalls and in the middle of California's redwood forests, Mexican drug gangs are quietly commandeering U.S. public land to grow millions of marijuana plants and using smuggled immigrants to cultivate them.
Pot has been grown on public lands for decades, but Mexican traffickers have taken it to a whole new level: using armed guards and trip wires to safeguard sprawling plots that in some cases contain tens of thousands of plants offering a potential yield of more than 30 tons of pot a year.