The Tri-County Volunteer Fire Company was founded by 26 men on April 15, 1950, and offically became a non-profit organization on June 7, 1950, with the first meeting occuring at the Riverview Tavern on Route 24. The name "Tri-County" derives from the fact that the fire company originally covered portions of Warren, Morris, and Hunterdon Counties.

The first major piece of equipment purchased from the fire company was a 1924 Brockway pumper, a sufficient quantity of hose, and other necessary firefighting equipment. Shortly after, Tri-County's first firehouse was constructed and completed in 1954. Until the firehouse was completed, equipment was stored in a barn off of Stephensburg Rd. As the years went by, the fire company experienced more and more fires and was decided more equipment, as well as expanding the firehouse, was needed. A 1957 International was purchased, and expansion began which included three truck bays, a Chief's office, and a modern kitchen.