Two marijuana-growing sites, one across the street from a school west of Fresno, were raided Wednesday morning. Three people were arrested.
Almost 2,000 plants were seized at the sites. Fresno County Sheriff Margaret Mims said two of those arrested will face federal charges and one will be prosecuted under state law.
Sheriff's deputies conducted the raid with help from the federal Drug Enforcement Administration.
John Donnelly, DEA resident agent in charge, said seizures were part of what he called "Operation Mercury" and took place after the growers ignored warning letters from the federal agency that marijuana cultivation remains illegal under federal statutes despite California's medical marijuana provisions.
"These folks declined to cooperate" with warning notifications from the DEA, Donnelly said.
"If we come to your door, you've had your chance."