Officers executed 29 search warrants in Humboldt and Mendocino Counties and raided grow houses in Shelter Cove, Whitethorn, Redway, Ettersburg, Garberville, Miranda, Phillipsville, Arcata and McKinleyville.
Operation "Southern Sweep" targeted a large commercial cultivation and distribution organization.
"Californians voted for reasonable personal use of medicinal marijuana for qualified patients - not massive whole sale growing operations," Special Agent in Charge Sara Marie Simpson of the California Bureau of Narcotic Enforcement said.
As a result of the raids, the officers located about 10,000 marijuana plants and seized 30 firearms. The marijuana plants had an estimated street value of between $25 and $60 million.
"It's a large-scale, for-profit, commercial business," FBI Special Agent in Charge Charlene Thornton said. "The targets of our investigation are reaping huge profits while contributing to the crime and violence oppressingcommunities around the state."
While one arrest was made during Tuesday's raids, no charges have been filed and none of the targets of the investigation have been arrested.