Ralph Grunewald, 89 of Sheboygan, passed away peacefully at Sharon Richardson Community Hospice on Tuesday, March 17, 2026. He was born on November 17, 1936 to Harley and Hildegard (Mahler) Grunewald in Sheboygan, WI. Ralph is a 1954 graduate of Howards Grove High School, furthering his education at Lakeland College in Chemistry. He later attended Purdue University completing his masters and PHD programs in bionucleonic in 1965.
In January of 1960, Ralph met the love of his life, Judith M. Pfenning at the Eagles Club dance where he asked for a dance and the rest was history! They were united in marriage on September 1, 1962 celebrating over 60 years together until her passing in July of 2023.
For 25 years, Ralph served as an assistant/associate professor at UW-Milwaukee, specializing in research and educating students around radioactive materials and its regulations until 1992. He also served as the radiation safety officer at the medical college of Wisconsin full time until the end of the last century (December of ’99.)
Ralph’s love for the environment extended into his past time, enjoying over three decades tending his acres of prairie containing native Wisconsin flowers and grasses. He looked forward to each new season of beauty from Bee Balm and cone flowers to the last bloomer, the blue Bottle Gentian. With his lifelong love for dogs and cats, it’s no surprise that he most recently enjoyed a special bond with 5 kittens that came to him in 2019. Ralph also enjoyed his role as handyman, regularly working on projects around the homestead. When Ralph wasn’t busy caregiving and working with his hands, you could find him engaging his mind—surrounded by books and reading to learn- with his most recent research in nutritional health. Ralph found joy in sharing his knowledge and wisdom gained from his findings with all those he encountered, most recently with the in-home caregiving staff at Embrace. His warm smile and caring nature will be deeply missed by those who knew him.
Ralph leaves behind his beloved daughters: Kristine (Michael) Siegenthaler of Tulsa, OK and Lisa Grunewald of San Diego, CA. He is further survived by his grandsons Carson and Jackson Siegenthaler, as well as nieces, nephews, and other relatives and friends.
Ralph was preceded in death by his wife, Judy and his sister, Diane (Peter) Lutzke.
The family plans to hold a private celebration of his life and legacy at their homestead in Sheboygan at a later date. In lieu of flowers, donations can be made in Ralph’s honor to Sharon S. Richardson Community Hospice.
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W2132 Garton Road, Sheboygan, WI 53081

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