Shirley C. Steffenson, 89, Mandan, passed away September 18, 2017 at Sunset Drive Prospera Community, Mandan. A memorial service will be held at 10 am on Saturday, October 7, 2017 at First Lutheran Church, Mandan. Cremation has taken place and the family will greet friends one hour prior to the service. Committal will take place at 1:30 pm at Sanger Cemetery. Shirley was born December 25, 1927 in Mandan to Ace and Mollie (Ringham) Richardson. She was raised and educated in Mandan, graduating from Mandan High School. Shirley worked at Sears and in 1947, while standing up as marriage witnesses for mutual friends, she met Richard Steffenson. They were married in 1948 and moved to the farm where they shared their life together and raised their children. A beloved mother, grandmother, and great grandmother, she will be missed by all who knew and loved her. Blessed to have shared her life is her husband of nearly 69 years, Richard Steffenson, Mandan; daughter, Susan (Clarence) Voigt, Mandan; 6 grandchildren, Julie (Max) Lazinger, Columbia, MO, Mike (Tina) Steffenson, Beulah, Roxanne (Collin) Jabolonsky, Bismarck, Lisa Voigt, Hot Point, NC, David Steffenson, Bismarck, and Danelle (Noah) Kraft, Colorado Springs, CO; and 9 great grandchildren. Shirley was preceded in death by son Rick in 2014; her parents; brother, Leon; sister, Grace; and great grandson, Marius. The family wishes to thank the amazing staff at Sunset Drive Prospera Community for all of the love and kindness they showed Shirley.