Narcotics detectives busted an illegal marijuana grow near Lopez Lake on Thursday, according to the San Luis Obispo County Sheriff's Office.
Sheriff's officials say the grow was located on both private property and national forest land near Hi Mountain Road.
Detectives reportedly seized 3,003 budding cannabis plants that the sheriff's office says, if allowed to mature, would have been worth an estimated $20 million.
They also reportedly discovered that a nearby creek had been dammed so water could be diverted to the marijuana plants.
Officials say the illegal grow was spotted by members of the Sheriff's Cannabis Enforcement Team during a reconnaissance mission a few days ago.
Investigators believe the grow may be part of a Mexican National cultivation operation.
No arrests have been made.