Agents Seize $1.2 Billion Worth of Pot in Calif.
Local officials said several Mexican marijuana-growing cartels helped set up the grow sites scattered throughout rocky mountainsides of eastern Fresno County, and warned more arrests were likely as the sweep continues.
More than 318,000 marijuana plants were destroyed in the operation, which also netted nearly $41,000 in cash, 25 weapons and two vehicles, Fresno County Sheriff Margaret Mims said Thursday.
"You can imagine looking from a helicopter down onto a forest, there are a lot of different shades of green. It took some specially trained personnel to spot where the marijuana was growing," Mims said. "We found it planted on hillsides and gullies, and some of the plants had grown to be eight feet tall."
While the bust was large enough to merit a visit Wednesday from Gil Kerlikowske, director of the White House's Office of National Drug Control Policy, it accounts for a small percentage of the pot typically seized in California each year.
Last year, more than 5.2 million plants were uprooted in all federal and state operations that reported seizures to the U.S. Drug Enforcement Administration.
"Operation Save Our Sierra" began several months ago, and has involved more than 300 personnel from 17 local, state and federal agencies.
Officials said some of the Mexican citizens arrested in the bust were nabbed in previous years' raids on gardens further south along the mountain range.
Some suspects already have been deported, and others will be prosecuted locally for charges ranging from conspiracy to possess and distribute pot to depredation to public lands, Mims said.
Still, officials with the state Department of Justice cautioned that the eradication efforts have touched only a small portion of the marijuana farms and that the damage to the environment can have a lasting impact.
Over the next few weeks, a crew of 40 volunteers will go back to the gardens tucked on remote U.S. Forest Service land and private property to chop down plants, pull out miles of drip lines and pick up trash and toxic chemicals.
"They had pesticides, fertilizers and rat poison in there," Mims said. "And at the bottom of the hillside where our agents found the largest grow, there was a creek bed. The first rain we got, all that would have washed down the creek."
More At CBS News' Special Report: Marijuana Nation