STEVE INSKEEP, Host:
NPR's Richard Gonzales looks at one example in California's Bay Area.
(SOUNDBITE OF RUSTLING - MEN WALKING THROUGH BUSHES)
RICHARD GONZALES: In a remote section of the Point Reyes National Seashore, about an hour north of San Francisco, two park rangers - one carrying a sidearm - plunge through a wall of blackberry and poison oak that's over their heads.
GUSTAVO CUNDAR: Some of these trails you have to squat through low. You would think they had hobbits working for them.
GONZALES: Back then, rangers found a plot of more than 22,000 marijuana plants worth an estimated $50 million on the street.
JOHN DELLOSSO: Why don't we take a walk maybe towards the stream and see what we can see over there?
GONZALES: Ranger John Dellosso leads us to a nearby stream, as he points to thousands upon thousands of feet of coiled irrigation hoses.
DELLOSSO: They needed a perennial source of water to grow these plants, and so these streams - which contain federally threatened Coho salmon and steelhead trout - the water is either being dammed up or siphoned out. And in both cases the water is being removed, regardless, to irrigate these plants.
GONZALES: John Dellosso.
DELLOSSO: Look at that. A circular pit, probably four-plus feet deep, about five to six feet in diameter filled with styrofoam, cans, bottles, plastic garbage bags - so literally, that's where all their garbage went.
GONZALES: Dellosso says this isn't the job he signed up to do as a park ranger.
DELLOSSO: To us, the National Park System, what's gone on here has really gone to the very essence, the very core, of what we do, which is to protect these natural resources and also to provide for safe recreational opportunities for the public. And this, you know, this really hurts.
GONZALES: Federal Drug Czar John Walter says more than a million pot plants were eradicated from California's state and federal parks last year.
JOHN WALTER: For every acre of forest that's planted with marijuana, about 10 acres are damaged by a toxic chemical runoff, diversion of water, damage to the surrounding environment. It costs about $11,000 per acre to repair and restore the land, given our past experience with these eradication efforts.
GONZALES: Cleanup costs are pressing the National Park Service, not to mention states and cities facing the same burden. Meanwhile, drug gangs are getting rich raising their marijuana on public lands says Eric Antebi of the Sierra Club.
ERIC ANTEBI: Just for example, in the last year, in Sequoia Kings Canyon National Park, agency staff there pulled out about 40,000 marijuana plants. That has a street value of about $160 million. For comparison, the entire budget of Sequoia Kings Canyon National Park is about $12 million. That's what they're up against.
GONZALES: Back at Point Reyes National Seashore, Rangers Dellosso and Cundar point to the little sprouts of marijuana growing from stalks cut just days ago.
DELLOSSO: Trust me, everywhere you look - you start looking now, you'll see them. So...
CUNDAR: Now you know why they call it weed.
GONZALES: Richard Gonzales, NPR News, San Francisco.
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