Mary O. Miller, 71, of Dayton, passed away on Wednesday, May 6, 2015, at the Sheridan Memorial Hospital surrounded by her loving family after a long courageous battle with lung disease.Mary was born August 27, 1943, to John and Ione (Long) O\'Brien. She was the 5th of 11 children. Mary and William (Bill) Miller were married on June 19, 1962, and settled on the Miller Ranch on Lodge Grass Creek. Together they had three children; Kelly Jo (Alan) Ripley of Bozeman, MT, Billy (Brandi) Miller and Robert (Amber) Miller, all from Dayton, WY.Mary was preceded in death by her parents, and three siblings; Joan, Danny  and Ralph. Survivors include her husband, children, grandchildren; Clarissa, Jacob, Austin, Madison, Isaiah, Derrek, Cathy and Leroy, one great grandchild, Kylie, siblings; Louise, Johnny, Joseph, Loretta, Dolly, Pat and Mike, sisters in law; Marian Miller and Laura Ruth McGlothlin and many nieces and nephews.Services for Mary will be held at 10:00 a.m. on Tuesday, May 12, 2015, at the Dayton Community Church with Kenny Mikami. Kane Funeral Home has been entrusted with arrangements.