Mexican drug traffickers are finding prime new territory for their vast marijuana growing operations: American’s national forests. They are planting illicit crops on public land, creating risks for people using the forest and and leaving behind pollution and trash. Drug organizations find it easier “to grow within this country” than to risk bringing marijuana across the U.S.-Mexico border, says Wisconsin Attorney General J.B. Van Hollen.

Benjamin Wagner, U.S. attorney for the Eastern District of California, which has been dealing with the problem for years, says it makes sense to drug traffickers "to move marijuana cultivation … closer to your point of sale." An August raid in Wisconsin’s Chequamegon-Nicolet National Forest resulted in the seizure of more than 8,000 marijuana plants and the arrests of seven people.