Frederick Otto Mahnke

Frederick Otto Mahnke departed this life for eternal life in heaven on February 3rd, 2026. His time of grace upon this earth was 91 years, 5 months, and 16 days.

Frederick was born in Green Bay, WI, to Paul and Lorena (nee Bubolz) Mahnke on August 18th, 1934. He became God’s adopted and redeemed child through the sacrament of Holy Baptism by Pastor Harold Eckert on September 16th, 1934, at St John – St James Lutheran Church in Reedsville, WI. He learned about his Savior’s love as a student at St John – St James Lutheran Elementary School. He publicly confessed his faith in Jesus Christ and was confirmed in the Christian faith by Pastor Eckert at St John – St James on June 5th, 1949. His confirmation verse was John 3:16.

Frederick continued his Christian education at Northwestern Preparatory School in Watertown, WI, graduating in 1953. To fulfill his dream of becoming a teacher, he attended Doctor Martin Luther College in New Ulm, MN, and graduated in 1957. By God’s grace, he served 43 years in the public ministry of the gospel as a principal and teacher at St John in Glencoe, MN; Emanuel in St Paul, MN; and David’s Star in Jackson, WI. He was privileged to mentor and encourage many student teachers as well as experienced teachers as a school visitor. Additionally, he served as the president of multiple principal conferences, the governing board of Kettle Moraine Lutheran High School in Jackson, WI, and on church councils and school ministry boards. Frederick sang in church choirs, taught Sunday School, and enjoyed coaching football, basketball, and softball.

Frederick married Naomi Kuske on August 6th, 1961, at Immanuel Lutheran Church in Waupaca, WI. His father-in-law, the Revered Paul Kuske, officiated. The Lord blessed their marriage with three children: Lisa, Jeffrey, and James. His love for them was never doubted as he (and Naomi) faithfully attended all their musical and sporting events as they grew up.

Frederick lived a full and meaningful life. As a child, teenager, and young man, he enjoyed playing sports, especially basketball and baseball. Listening to games on his am radio as a boy on the family dairy farm, he became a lifelong fan of the Chicago White Sox. He also loved to cheer on the Milwaukee Brewers, Milwaukee Bucks, and the Green Bay Packers. He was a gardener and planted and cared for numerous trees on their property. He was an avid golfer until the age of 88. In addition to golfing in every state, he also golfed in numerous foreign countries. He loved to bowl and he played on many bowling teams with many dear friends. He enjoyed photography and took countless pictures of family events, gatherings and vacations.

Frederick did not slowdown in retirement from teaching in 2001. He and Naomi traveled to 19 foreign countries with their dear friends. Fritz worked at the Wisconsin State Fair and especially enjoyed serving as an usher for the Milwaukee Brewers. In 2019 the family home in Kirchhayn was sold, and Fritz and Omi moved to OnaTerrace in Onalaska, WI. When his health allowed, he enjoyed attending games and concerts at Luther High School.

Fritz is survived by his wife of 64 years, Naomi, and their three children, Lisa (Dan) Muszytowski of Elcho, WI, Jeffrey (Stacy) Mahnke of Weston, WI, and James (Dorann) Mahnke of Onalaska, WI. He is further survived by eight grandchildren: Robert Schuett, Zachary (fiancée Dani Peterson) Schuett, Amanda (Trevor) Kuehn, Brianna (Daniel) Smerchek), Alissa Mahnke, Cierra Mahnke, Benjamin (Brooke) Mahnke, and Grace Mahnke. Frederick was a proud great grandfather to three great granddaughters: Lily and Everly Smerchek, and Rikki Mahnke. He is also survived by his sister, Mareolin Kuske, two brothers in law, Pastor Norman and Philip Kuske, and a sister in law, Elaine Kuske. Finally, Fritz is survived by cousins, nieces, nephews and friends.

Fritz was preceded in death his parents, Paul and Lorena Mahnke; two brothers in law, Pastor Theodore Kuske and Professor David (Gwen) Kuske, and two uncles, Karl (Ruth, Carol) Bubolz and Gerhard (Bergetta) Bubolz.

Funeral services will be held on Friday, February 6, 2026 at 4:30 PM at St. Paul’s Lutheran Church, Onalaska. Pastor Daniel Olson will officiate. Friends may call at the church on Friday from 3:30 PM until the time of services.

Fritz’s body will be laid to rest at the cemetery of St John – St James Lutheran Church to await the resurrection of all the dead when our Lord and Savior Jesus Christ returns in glory on the Last Day.

The family thanks the loving and helpful staff of Emplify Home Health & Hospice as well as the nurses from Commonheart who compassionately cared for Fritz.

The Lord gave, and now the Lord has taken away. May the name of the Lord be praised.