John A. "Jack" Manthey

John A. “Jack” Manthey, age 89 of Janesville, passed away on April 2, 2026, at St. Mary’s Hospital, Madison following a brief illness. He was born on June 7, 1936, in Janesville, the son of John J. and Rose M. (Urbanowski) Manthey. Jack grew up on the family farm in Harmony Township where he would reside for the rest of his life. He was a 1955 graduate of Janesville High School and served in the U. S. Naval Reserve for 8 years. Jack was employed for over 30 years by JATCO as well as farming on the family farm for most of his life.

In his early years, Jack enjoyed boating and water skiing at the family cottage at Lake Koshkonong where he also enjoyed ice fishing. Later he developed a special passion for fishing on the Mississippi River in Ferryville, Wis., where later in life, he purchased land and spent much of his time there. He enjoyed deer hunting with family and friends near Hatfield, Wis., and later, on his land in Ferryville. Jack will be remembered for the joy he received from being at family gatherings during the holidays and at the family cottage on Lake Koshkonong. Above all else, Jack was a farmer at heart and a steward of the land. Jack enjoyed raising a very large garden, canning the produce and sharing his bountiful harvest with family and friends. He was a conservationist for the benefit of wildlife. He was always willing to lend a hand to build or fix anything. Jack was a member of Nativity of Mary Catholic Church.

Survivors include his brothers and sister, Wayne (Bonnie) Manthey, Bruce (Cheri “CJ”) Manthey, Kathleen Quarterman, and Larry (Lynn Holland) Manthey; and 10 nieces and nephews. In addition to his parents, Jack was preceded in death by his brother, William Manthey; sisters-in-law, Judy Manthey and Jan Breunig; and brother-in-law, Donald Quarterman.

A Mass of Christian Burial will be held at 11 a.m. on Friday, April 10, 2026 at NATIVITY OF MARY CATHOLIC CHURCH, 313 E. Wall St., Janesville. Visitation will be at the church on Friday, from 9:30 a.m. until the time of Mass. Entombment with military rites by Kienow-Hilt V.F.W. Post # 1621 will follow at Mount Olivet Cemetery Mausoleum. In lieu of flowers memorials to SSM Health at Home Hospice or Southern Wisconsin Ducks Unlimited would be appreciated.

HENKE-CLARSON FUNERAL HOME is assisting the Manthey family. Online condolences can be shared at www.henkeclarson.com.