Local, state and federal law enforcement agencies served 10 search warrants and five arrest warrants in El Dorado and Nevada counties last Tuesday to shut down a major marijuana-growing operation in Northern California.

"This illegal operation consisted of thousands of marijuana plants worth millions of dollars and protected by handguns, shotguns and rifles," Attorney General Jerry Brown said in a release from the El Dorado County Sheriff's Office. "These illegal growing operations are a threat to public safety."

In the course of the Dec. 16 crackdown, agents seized approximately 2,100 marijuana plants and 100 pounds of processed marijuana, plus indoor marijuana-growing equipment, such as lights and generators. Agents also found approximately $625,000 in U.S. currency and seized two handguns, three rifles and five shotguns. Several of the weapons seized were loaded.

The two-month investigation began in September, after agents observed an outdoor marijuana cultivation operation in Pollock Pines. Agents found that, in the past four years, the suspects had spent millions of dollars on properties in El Dorado, Nevada, Placer, Mendocino, Sacramento, Alameda and San Francisco counties. During the investigation into these properties, agents discovered large indoor marijuana cultivations in El Dorado County.

Law enforcement agents detained several individuals. Any individuals arrested last week will face federal charges of conspiracy to manufacture/cultivate marijuana, according to the release. The arrests were part of a multi-agency operation involving more than 200 law enforcement personnel from across the state.

The same day that Sacramento sheriff's authorities were assisting with the massive operation, that county's board of supervisors voted 4-1 to adopt a medical marijuana identification card system, making it the 48th of 58 counties to comply with the requirements of a voter initiative passed in 2003.

The only counties larger than Sacramento that have yet to adopt similar ID card programs are San Diego and San Bernadino, both of which have unsuccessfully challenged the program in court. The San Diego Board of Supervisors plans to make a final appeal to the U.S. Supreme Court. Ventura County implemented its ID program Dec. 15.

Possession of marijuana, even for medicinal purposes, remains a crime at the federal level, putting California law in direct conflict with the federal government's.