Robert Craig "Evel" Knievel had a fleet of support vehicles which all had Montana license plates on them - one of which was his personal truck, R/V, and dressing room.  As you watch old videos of Evel at Snake River, Caesars Palace, and other venues, he usually emerges from a 1974 Mack Motor Home.  This truck has recently been restored and is a rolling museum to Evel.  There are shots of the truck with this Montana EVEL license plate on it.  The plate also sometimes appeared on Evel's Cadillac.  In 1975, the state of Montana produced license plates in this style that are debossed, rather than embossed like the rest of our plates.  It can be difficult to tell from the images that all of the white parts of the plate are pressed inward, rather than raised.