Dean T. Koch, age 80 of Rock City, IL, passed away on Tuesday, July 7, 2026 at UW Madison Hospital in Madison, WI. He was born October 25, 1945 in Pearl City, IL; the son of the late Harold and Emma (Otte) Koch. He attended Pearl City High School and graduated from Dakota High School. Dean married Bonnie Baumgartner on September 26, 1964.

He was a lifelong farmer and also worked at Rawleigh and Bach’s Eversoft in Freeport, IL. Dean and Bonnie attended Hope Evangelical Free Church in Monroe, WI. Dean was a member of the FFA at Pearl City and Dakota and also of the Stephenson County Dairy Herd Improvement Association.

His passion was farming. He loved growing things and taking care of animals. He also enjoyed woodworking, mowing, and gardening. He was very detail oriented and made several pieces of furniture for their home. He also loved to spend time with his grandkids and great grandkids on the farm.

Dean is survived by his wife, Bonnie Koch; children, Donna (Jim) Sears, Terry (Deb) Koch, Connie (Jim) Alber, and Jodie (Scott Rosonke) Elmer; 11 grandchildren; 14 great grandchildren; and 2 great great grandchildren with one on the way; brothers, Eugene Koch, Kenneth (Sharon) Koch, Roger Koch, and Don (Rita) Koch; sister, Katherine Slamp; and several nieces and nephews. He was preceded in death by his parents; sister, Sharon (Mert) Hollard; sister-in-laws, Sally Koch and Kathy Koch; and brother-in-law, Richard “Dick” Slamp.

The funeral service will be held on Thursday, July 16, 2026 at 11:00 a.m. at the Daughenbaugh Funeral Home in Dakota, IL. There will be a visitation before the service beginning at 10:00 a.m. Interment will take place at Chapel Hill Memorial Gardens in Freeport. A memorial fund has been established in his name for arthritis and Parkinson’s research. Condolences may be shared with his family at www.walkermortuary.com.