Mary S. Kostyack, 81, of Barnes, PA., died Monday, April 22, 2024, at Penn Highlands of Dubois, PA., after an extended illness. She was born November 24, 1942, in Warren, PA. Mary was the daughter of Harry and Eleanor Carlett O'Donnell. She has resided in Barnes, PA., for the past 22 years. Mary was a member of the Sheffield Senior Center and Sheffield Rod & Gun Club. She enjoyed crafting, and time spent with her family, especially during the holidays. She is survived by her husband of 36 years, Michael R. Kostyack, whom she married in October of 1987, her son, Scott Dahl and wife, Teri of Dubois, PA., 1 Brother – Dennis "Denny" O'Donnell of St. Augustine, FL., 2 Grandsons – Matthew and Tyler Dahl. In addition to her parents, she was preceded in death by her 1st husband, Marshall Dahl. Friends may call at the Donald E. Lewis Funeral Home, Inc., 304 East Street, Warren, PA. on Thursday, April 25, 2024, from 12:00 noon until 1:00 P.M. A funeral service will be conducted at 1:00 P.M. with Rev. Dr. Dale Haight, officiating. Interment will be in Oakland Cemetery, Warren, PA. Those wishing to place memorials may do so through Hahne Cancer Center, 100 Hospital Avenue, DuBois, PA. 15801. E-mail condolences may be sent by visiting www.lewisfuneralhomeinc.com < www.lewisfuneralhomeinc.com/ >