Dennis first attended a tractor pull in 1967 and the sport quickly caught his attention. In 1968 he built his first single engine modified tractor. Shortly after, Dennis began competing with the Minnesota Tractor Pullers Contest Corporation (MTPCC) and was President of the MTPCC when they and Gopher State Pullers became the United Pullers of Minnesota. Dennis has also been on the NTPA Board of Directors since 1974. Dennis and his wife, Sharon, live in Glencoe, Minn. and have been married for 41 years. They have three children: Doug, Kim and Chad, and 10 grandchildren. Their children have grown up pulling and currently pull "Pack Rat VI" (Doug), "Pack Rat VII" (Kim) and "Pack Rat V" (Chad). Sharon videotapes the events and Kim and her husband, Rick, take pictures for the pulling team and also for The Puller magazine.