Jeanette Koski

She was born at home on ‘D’ Street in Ishpeming, Michigan to Ralph and Elsie Fosmo on February 19, 1935. She attended Ishpeming Public Schools starting at Junction School and graduating from high school in 1953. She earned a Bachelor of Science degree in education from Northern Michigan University (NMU). Jeanette first met her husband, Ronald Koski while attending NMU, they wed in August of 1960 and were married for more than 60 years.

Jeanette’s passion in life was downhill skiing. She skied with her dad every week in the Upper Peninsula, with Ron and their three daughters in the Midwest most winter weekends, and for several years traveled to Colorado to ski with friends. She continued to ski into her 80s.

Jeanette had a long career as an elementary school teacher beginning in Champion. Township and followed by Waterford Township School Districts in Michigan. After having her three children, she began teaching part-time as a Title 1 teacher before returning to a full-time role teaching first grade in Fond du Lac, Wisconsin. She retired in 1994 after 20 years of teaching.

While living in Fond du Lac for more than 35 years, she was an active church member at Immanuel Trinity Lutheran Church. When she moved to Sun Prairie, she became an active member at Our Savior’s Lutheran Church. Jeanette was also known for her love of baking, especially several types of cookies during the Christmas season, and for cocoa brownies from the Betty Crocker Cooky Book.

Survivors include her children, Caroline (Gary) Zeimet of Rio, WI, Kelly (Steven) Marianno of Fairfield, CA, Jill (David Ferguson) Koski of Wheaton, IL; grandchildren, Maura Towey of Los Angeles, CA, Tait Ferguson of Cleveland, OH, and Annika Ferguson of Cincinnati, OH. Other survivors include her sister, Carol Moilanen, her niece, nephews, and their loved ones.

She was preceded in death by her husband Ronald Koski, brothers, Ralph Fosmo and Russell Fosmo, and her parents, Ralph and Elsie Fosmo. A memorial service will take place at 11AM on Saturday, November 1, 2025 at Our Saviorás Lutheran Church, 550 Lincoln Dr., Sun Prairie, WI 53590. A visitation will take place from 10AM until the time of service. In lieu of flowers, donations may be sent to Trinity Lutheran Church in Ishpeming, MI, Isle Royale and Keweenaw Parks Association, or the US Ski and Snowboard Hall of Fame & Museum.

Please share your memories at www.cressfuneralservice.com.

Cress Funeral & Cremation Service, 1310 Emerald Terrace, Sun Prairie (608) 837-9054