Dennis was born October 9, 1940 in Volga, SD to Oliver and Lydia (Stephen) Jorenby. He graduated from Volga High School and moved to southern California where he worked as a shoe salesman and at Sears. On May 29, 1959 he was united in marriage with Arlys Holvick, his high school sweetheart. They began their married life in Downey, CA before moving back to Volga, SD where Dennis worked as a feed grinder. Dennis and Arlys then moved to Sioux Falls, SD where Dennis opened a catering business. In 1962, they moved back to CA where Dennis worked for Knutson Creamery. At age 23, Dennis moved into the service station business, becoming, at the time, the youngest owner and dealer of a Mobile Oil service station. While on a pheasant hunting trip in South Dakota in 1972, he found the property at Lake Campbell, where he had first met Arlys roller skating, was for sale. Dennis expanded the property to not only roller skating but also camping, a snack shop, an ice cream shop, a gas and service station, and a market. In 1983 they moved back to California where Dennis was once again in the service station business. They returned to Lake Campbell in 1993, where Dennis kept busy as a mechanic, handyman, tree stump grinder, and backhoe operator.
Dennis is survived by his wife, Arlys; their children, Shelly Thompson (Bob), Shawn Jorenby (Geraldine), Timothy Jorenby, Bethanny Shea (Jonathan); son-in-law Mark Druskoff; grandchildren, Kaitlyn Thompson, Emily Brito, Melissa Thompson, Rachel Thompson, Amanda Druskoff, Chloe Druskoff, Tyler Druskoff, Aidan Druskoff, Gracie Druskoff, Jakob Druskoff, Cody Druskoff, Camille Jorenby and Brendan Jorenby; great-grandchild Hayde Dahlmeier; and sister Marlene Landsman (Bill), Elkton, SD. He was preceded in death by his parents and children Ronda Jorenby, Wade Jorenby, Gregory Jorenby, Paula Jorenby-Druskoff, and Robert Jorenby.