Inmates could be seen sitting on the ground of the exercise yard in the minutes after the riot scene was declared under control.
Folsom prison was under lockdown Wednesday following a riot that left several inmates with stab wounds and gunshot wounds.
The gunshot wounds happened when guards opened fire in their attempt to quell the riot. Prison spokesman Sgt Tony Quinn told KCRA when gunfire is used it means "imminent loss of life."
A press release issued by the prison said prison staff used, "pepper spray and rubber projectiles and fired shots to quell the incident." Quinn said officers also used rounds from a Mini-14 semi-automatic rifle.
The riot lasted about 10 minutes, involved more than 150 maximum security imates, and broke out around 12:40 p.m.
This all happened at California State Prison in Sacramento, which is about 20 miles east of the state capital. The prison is known as "New Folsom prison" and is next door to the much older Folsom State Prison, which became infamous due to singer Johnny Cash.
It houses some 2,800 inmates. Many are there because they caused trouble at another prison and were transferred.
The Department of Corrections said some of its employees also suffered minor injuries in the melee. Quinn said the workers who were hurt were treated on the prison grounds.
Several ambulances were seen leaving the prison grounds Wednesday afternoon. In all 11 inmates were taken to the hospital. The release said the inmates required treatment for stab wounds, gunshot wounds and blunt force trauma.
All but two were released back to the prison by Thursday morning. One was being treated for a gunshot wound to the leg and the other for a possible broken shouler.
Prison staff said they found five "inmate-manufactured" weapons after the incident.
It was not clear what sparked the riot.