Jack Harold Mammen, age 80, a resident of Chillicothe, Missouri, passed away peacefully on Tuesday, July 7, 2026, at Hedrick Medical Center, Chillicothe, Missouri. Jack was born the son of John and Nevis (Hall) Mammen on May 3, 1946, in Chillicothe, Missouri.

Jack dedicated his professional life to his work as a mechanic at Chillicothe Diesel in Chillicothe, Missouri, where he was known for his skill and integrity. His commitment to his country was exemplified through his service in the United States Army. A man of many interests, Jack was a member of the Chillicothe Eagles and a member of Pleasant Grove United Methodist Church. He found joy in the great outdoors, spending countless hours fishing, hunting, and camping. He also enjoyed spending time with his family.

Jack was a devoted husband to his cherished wife, Charlotte Fay (Hinnen) Mammen. They were united in marriage on August 6, 1967, in Chillicothe, Missouri and shared 59 wonderful years. Together, they built a loving family that includes their son, Kevin Mammen and his wife Heather of Chillicothe, Missouri, and two daughters, Christy Shiflett and her husband John of Meadville, Missouri, and Peggy Zorn of Meadville, Missouri. Jack was a proud grandfather to ten grandchildren: Courtney (Brandon) Swindell, Bobbi Jo Corbin, Chris (fiancé, Jodi) Corbin, Brittney (Kodie) Barrett, Mackenzie Mammen, Michaela Mammen, Ashlee (fiancé, ) Mammen, Carson Zorn, Jacob Shiflett, and Johnathan Shiflett; and eight great grandchildren, He is also survived by his sister, Judy (Bob) Pyrtle, his sister-in-law, Sandy Mammen, and several nieces and nephews. Jack was preceded in death by his parents, John Mammen and Nevis Adrice (Hall) Mammen, as well as his brothers, Jerry Mammen, Johnnie Mammen and Robert Mammen, and his sister, Carol Lollar.

Funeral services will be held at Lindley Funeral Home, Chillicothe, Missouri, on Thursday, July 9, 2026 at 11:00 a.m. A scheduled visitation will be held at Lindley Funeral Home, Chillicothe, Missouri, on Thursday, July 9, 2026 at 10:00 a.m. until time of service. Burial will be held at Resthaven Memorial Gardens, Chillicothe, Missouri. Memorial contributions may be made to Chillicothe Fraternal Order of Eagles and/or Jack Mammen Memorial (Please make checks payable to Charlotte Mammen) and may be left at or mailed to Lindley Funeral Home, P.O. Box 47, Chillicothe, Missouri, 64601. Online condolences may be made at www.lindleyfuneralhomes.com.

Arrangements are under the direction of Lindley Funeral Home, Chillicothe, Missouri.