About 2,000 inmates are working alongside 12,000 other firefighters to combat the deadly and widespread California wildfires.
The Mendocino Complex Fire has burned through about 350,000 acres of northern California. In total, 146 homes and more than 1,000 buildings remain under threat from the state's largest fire in history.
The 2,000 inmates are members of the California Department of Corrections and Rehabilitation volunteer firefighting program.
The inmates earn $2 a day and $1 an hour for fighting active fires, according to CNBC.
The firefighting inmates also earn time off of their prison sentences.
"Each volunteer inmate is evaluated individually to ensure that all those selected for the camp program are willing to be team members with nonviolent behavior, even if their original conviction was for a violent crime," CDCR representative Vicky Waters told CNBC.
Inmates who have "minimum custody" status qualify to be a volunteer. Inmates who committed arson, rape or sex offenses won't qualify. Those who have active warrants or medical issues are also disqualified from the volunteer program.
The inmate volunteers live in "conservation camps" where they do physical labor, including cutting brush and trees to stop the fire from spreading. The inmates also help clear any flood channels, storm drains and clear out hiking trails for people in the area, CNBC reported.
"They do similar work to any firefighter, working long hours and sleeping in camps with other inmates. Most are on the front lines, using chain saws and hand tools to reduce tinder-dry brush and trees to stop the flames," according to the Associated Press.