More than 550 marijuana plants growing in a creek bed near Highway 227 and Price Canyon Road were discovered on Monday by the San Luis Obispo County Sheriff's Dept.
The plants were hidden by overgrown vegetation. A tip led authorities to the site.
No one has been arrested, although officials say there was other evidence left at the scene that may provide clues to the identity of the growers.
The giant, leafy plants with an estimated street value of more than $1 million were eradicated.