National Parks' Pot Patrol

Marijuana farmers are moving into national parks like Yosemite—but vigilant rangers and agents are waiting

It's no secret that America's national parks have a weed problem. Each year, rangers discover more illegal marijuana crops grown on public lands, and the cartels are even invading West-Coast beacons like Yosemite and North Cascades. Besides contributing to an enormous illegal cash crop, these clandestine cannabis lots wreck the pristine wilderness that surrounds them.

Not that the park service is taking it lying down: Special agent rangers stalk through the parks, bushwacking as quietly as they can in order to bust as many farms as possible. In practice, it sounds like real Jason Bourne-type stuff, except with hiking instead of neck snapping and roof jumping as the primary action.

They're on what they call a "creep": a stealthy hike through an area that's been used in the past by pot growers. They step carefully, because even the snapping of a dry branch could be enough to telegraph their presence to growers who might be hiding in these woods.

Though marijuana growers are sometimes armed and have caused a few close-calls in national forests with hikers, rangers insist that visitors to national parks are safe—in part because of their recon and law-enforcement efforts.

"People coming to Yosemite shouldn't fear this problem. Our job is to ensure that their visit is a safe visit, and we will ensure that. We do ensure that," (Yosemite chief anger Steve Shackelton) says.

Have you run into a pot farm or marijuana growers while hiking/camping/backpacking? What did you do?

—Ted Alvarez

Marijuana Farms take root in National Parks (NPR)