The Merced County Fire Department was established in 1855 by the County of Merced. The department had just a few stations, the exact number is unknown. However, during this time in the department's history, the personnel would build their own fire engines out of army surplus equipment. Some stations in Merced County had a residence where they raised their family in the stations. Most firefighters in this time had to have other jobs to help support them and their families. A normal shift would sometimes be five or six days on and one day off.
As the county grew, the department had up to 110 fire personnel and 22 fire stations. Due to fiscal constraints, on July 1, 1988, Merced County Fire contracted with the California Department of Forestry and Fire Protection (CAL FIRE). The once 110 personnel department with 22 stations is now 19 stations and a total of 77 career personnel. CAL FIRE is responsible for providing fire personnel to Merced County. Merced County is accountable for equipment, vehicles, facilities, support staff and the Extra-Help Paid Call Program to assist CAL FIRE personnel.