According to writer Don Creacy, in an in-depth article in the March 2009 issue of "Classic Images", Dennis had a life-long passion for flying and at one point abandoned his acting career to become a transport pilot. It didn't last long, however, after being injured in a plane crash which required a hospital stay of more than a year. Dennis also became a flight instructor at one point at a private San Fernando Valley airport to make ends meet. His aspirations of being a professional pilot were ended by the airplane crash incident.
He seriously injured co-star Jimmy Wakely in a 1945 knife attack which occurred after a night of heavy drinking and a budding professional jealousy over Wakely's popularity. Surprisingly, Wakely survived the attack and did not press charges. Moreover, Moore returned to co-star with Wakely in Rainbow Over the Rockies (1947) and Roaring Westward (1949).
Known in pictures for wearing a distinctive-looking gun belt and buckle.