California prison riots are violent disturbances that occur within the state's correctional facilities, often involving inmates clashing with each other or with prison staff. These riots can be triggered by various factors, including overcrowding, gang tensions, and disputes over resources. Notable incidents include the 1980 San Quentin State Prison riot and the 2011 Pelican Bay State Prison disturbance, which highlighted issues of inmate rights and prison conditions. The aftermath of these riots often leads to increased security measures and investigations into the causes of the unrest. California's prison system has faced ongoing scrutiny regarding its management and the treatment of inmates, prompting discussions about reform and rehabilitation efforts.