Trucks that are meant to go where there are no roads, bring along firefighters, water, equipment and tools to fight fires. They tend to be built on four wheel drive chassis and have a short wheel base. Most are built on a commercial chassis, but some a built with a standard fire truck cab. The models are 5 3/8 inches wide, over 6 inches in height and start at 20 inches in length.
U.S. Forest Service – International / Boise Mobile Equipment