In West Oakland, the Black Guerrilla Family, a prison-based gang, distributes heroin and commits violent crimes such as contract murders and robberies. The Black Guerrilla Family evolved from the 1970s radical prison movement in California, and is considered extremely violent. These upper-level traffickers buy heroin from Hispanic gangs in southern California. Production Opium is not cultivated in Northern California nor is heroin produced. In rare cases, ethnic Asians grow small plots of opium poppies in their backyard gardens for personal use.
Some groups transport heroin from the border directly to cities in Northern California.
From there, groups transport the heroin to secondary hubs in the Central Valley. A significant portion of this heroin is destined for distribution in San Francisco. The South Bay Area is also an important secondary hub, specifically San Jose, Redwood City, and East Palo Alto. In 1999, 8.7 kilograms of heroin were seized on Northern California highways. Most of the heroin seized during stops was being transported to destinations within the state.