Pot Farms Sprout in National Parks

America's park rangers are battling a growing number of marijuana plantations taking root in national parks, NPR reports. Marijuana farms have been found in at least six national parks on the West Coast, where rangers say growers camp in the woods all summer, tending hidden plantations that can't be spotted from the air, and laying down irrigation hoses up to a mile long.

The growers are mainly poor Mexicans, authorities say, laboring under the control of drug cartels that run large-scale growing operations across several states. Yosemite rangers are controlling the problem for now, but an official warns the farms are a "fast-moving threat" that pose a risk of increasing danger from criminals and pollution from pesticides.
(More marijuana stories.)