A task force of narcotics officers was airlifted into the plantation in the Los Padres National Forest north of the city of Ojai Wednesday, the Los Angeles Times reported.
They discovered water reservoirs being filled by natural springs and thousands of feet of irrigation hose throughout the area providing water to plants, the newspaper said.
They also uncovered a campsite with tents, stoves, sleeping bags, guns and ammunition.
No arrests were made.
There have been reports of Mexican nationals increasingly using public forest lands in California to grow marijuana without having to bring it over the U.S.-Mexican border, the Times said.