Mark Peter Koeplin peacefully passed away in his sleep on Sunday, January 22, 2017 at home in Glendale, AZ. Mark was born on June 7, 1950 in Fargo, ND, and was raised in Moorhead, MN. He attended St. Francis Catholic School and Moorhead High School Special Ed Classes graduating in 1969. Through his adult years, Mark worked as a janitor at Moorhead High School, Red River Human Services, Holland Nursery and Rex & Sons Auto Sales in Peoria, AZ. In 2001, Mark moved in to live with his brother and sister-in-law, Jon and Mary Koeplin in Glendale, AZ. Mark will be missed by his many relatives and friends who dearly loved and cared for him. Mark is preceded in death by his parents, Marvin and Leonette Koeplin, an infant sister, Pauline and his brother Wayne Koeplin and nephew Carey Michael Koeplin. Surviving Mark are his brother, Jon Koeplin (Mary) and his sister, Mary Kathryn Dickinson (Jim) and several nieces and nephews. Visitation will be at 10:00 a.m. with funeral services at 11:00 a.m., Wednesday, January 25, 2017 at Menke Funeral & Cremation Center Chapel, 12420 N. 103rd Ave., Sun City, AZ. In lieu of flowers, donations can be made to Mark’s Day Program, Developmental Enrichment Centers, 16809 N. 53rd Ave., Glendale, AZ 85306.