State and federal authorities fanned out across six Northern California counties in recent weeks in a broad attack on marijuana farms in U.S. forests, officials said.
More than 460,000 pot plants were destroyed and 101 people arrested in the raids in and around the Mendocino National Forest.
The action came in response to a proliferation of marijuana farms that are destroying ecosystems and scaring hikers away, Melinda Haag, U.S. attorney for Northern California, said at a news conference announcing the operation Friday.
"The Mendocino National Forest is under attack by drug traffickers," Haag said at the news conference in Ukiah. "Visitors to the forest are increasingly intimidated by the prospect of armed drug traffickers and illegal cultivation sites.
"I've warned people who come up here during the summer to be careful when they go hiking."
The latest effort, dubbed Operation Full Court Press, targeted 56 growing sites. Authorities seized 27 guns and 11 vehicles, Haag said.
The operation also confiscated fertilizers, chemical pesticides and rat poison. With the aid of the U.S. Forest Service, 23 tons of trash and 22 miles of irrigation pipe were removed; 13 man-made dams remain to be dismantled.
"There are those who believe that growing marijuana is a harmless, peaceful activity in harmony with nature," Haag said. "This notion is, in a word, wrong."
The effort involved more than 300 people working for 25 local and federal agencies.
Illegal drug organizations have grown pot in California forests — from the Cleveland National Forest in Southern California to the Klamath National Forest in the far north — for decades. But local, state and federal authorities have stepped up eradication efforts in recent years.
In 2008, 2.5 million marijuana plants were eradicated from national forests in California, almost five times the number destroyed in 2004, according to the National Center for Drug Intelligence. And California is the national focus of such efforts; 80% of all plant eradication in U.S. forests occurs in the state.