Dev Jennings learned to ski in Salt Lake City, but joined the 10th Mountain Division in World War II, serving first as a rock climbing and ski instructor and later as a combat rifle squad leader. With 10th Mountain, Jennings served under Bob Dole, later a US Senator and candidate for President in 1996. He skied for the University of Utah and Colorado State University, and represented the Aspen Ski Club. After the 1948 Olympics, Jennings opened Sporthaus, a specialty ski shop in Salt Lake City catering specifically to high performance skiers. He later became a ski official, serving as Assistant Chief of Course at the 1960 Winter Olympics in Squaw Valley. Jennings moved to New Hampshire in 1970 to become Executive Director of the Waterville Valley Association.