Terry W. Tellefson, 74, of Washington, IL, passed away at 9:10 pm Thursday, December 26, 2019 surrounded by his family. Terry was born on September 29, 1945 in Fort Atkinson, WI to Don and Bette Tellefson, both of whom preceded him in death. Surviving are his loving wife of 50 years, Mary "Carol" Tellefson, his brother, Dean (Bev) Tellefson of Aurora, CO; his three sons, Erik (Sarah) Tellefson of Chicago, IL, Ben (Sarah) Tellefson of Washington, IL, and Matt (Samantha) Tellefson of Burelson, TX, and his four grandchildren, Max, Lily, Sam, and Parker. Terry spent his life helping others through his career in social work, retiring from Advantage Behavioral Health Systems in Athens, GA. He and his wife retired to Holiday Shores Lake in Illinois where he enjoyed fishing, boating, golfing, and playing poker. Terry and his wife regularly attended their grandchildrens events and moved to Washington in 2019 to be closer to family. Terry was an organ donor. Cremation rites have been accorded and private services are scheduled. Deiters Funeral Home and Crematory in Washington is assisting the family. Memorials may be made to St. Jude Childrens Research Hospital or to Friends of Advantage in Athens, GA.