Sandra A. Mantz, 75, of De Pere passed away in Jacksonville, FL peacefully with her loving husband Tom by her side entering the gates of heaven on June 16, 2026. Sandra Ann De Ruyter was born on February 16, 1951, to Donald M. and Helen (Baeten) De Ruyter in De Pere. Sandy faced these past 22 months head on with positivity and dignity before succumbing to a very rare type of cancer. Sandy had a great work ethic. She worked for 49 years, beginning her employment in 1969 with Larsen Canning Company in Green Bay, as a key punch operator and retiring in 2018 from Bay Valley Foods in De Pere, from their IT Department.

Sandy was a beautiful, kind, caring and loving women who truly enjoyed life. She loved running, walking, hiking, biking and generally any outdoor activity, including gardening and yard work. She participated in over 40 Bellin runs and several January 1st Sheboygan Polar Bear plunges. She also enjoyed watching numerous sporting events which included the Packers, Brewers and golf events. Sandy was most comfortable when at their second home in Sheboygan, where she loved the relaxed surroundings and enjoyed several get-togethers with their Sheboygan friends.

Sandy will be very much missed by her devoted Husband, Tom, De Pere; Brothers, William (Cheri) De Ruyter, Sun City West, AZ; Donald De Ruyter, De Pere; Lawrence (Maureen) De Ruyter, Egg Harbor; her sister Lynn De Ruyter (Juin Charnell), Burnsville, MN and her sister-in-law Peggy (Scott) Langelin, Brookfield, WI, along with many nieces and nephews. She was preceded in death by her father and mother, brothers Bernard De Ruyter and Steven De Ruyter, and sister Susan De Ruyter.

A special “Thank You” to the excellent Oncology team of doctors and their staff from the Mayo Clinics in Rochester, MN and Jacksonville, FL for the wonderful care and treatment that Sandy received to help extend her quality of life. Also, “Thank You” to the Community Hospice and Palliative Center for Caring in Jacksonville, FL for the compassion and care they provided.

A private Celebration of Life for Sandy will be held by the immediate family.