Narcotics detectives found two makeshift greenhouses containing 3,500 marijuana plants near three tents and a mess hall type operation, Sgt. Chris Bertoli said.
The street value of the marijuana when mature is estimated at $10 million, Bertoli said.
Detective hiked down steep terrain about 15 miles west of Lake Sonoma and were able to sneak up on the tents, each occupied by a Mexican national, Bertoli said.
The suspects were arrested without a confrontation and the trio had supplies that would have lasted through the marijuana growing season, Bertoli said.
The area had been terraced and clear cut and water was diverted from a nearby spring, Bertoli said. Detectives found small animal traps and poisons next to the water source and throughout the garden site, Bertoli said.
Jesus Lopez, 61, of Vera Cruz, Roylan Carbajal, 50, of Jalisco and Victor Chavez, 38, of Michoacan were arrested for cultivation of marijuana and possession of marijuana with intent to sell, Bertoli said.
They were booked into the Sonoma County jail under no bail because of their immigration status, Bertoli said.