According to the sheriff's department, the operation started in Annapolis, before moving to the Cazadero area and the Salmon Creek area before ending in the hills west of Lake Sonoma.
Officials discovered plants ranging in heights from 2-4 feet. Gardens varied in size from several hundred to several thousand plants.
Evidence caused officials to believe that Mexican criminal organizations are financing and support the growing operations.
The estimated value of the plants found total about $1.8 million, the sheriff's department said.