Bonnie Lou Zebroski (Biggs), 91, of Keystone, South Dakota, passed away at home on December 14, 2025, surrounded by family.

Bonnie was born in Portland, Oregon, on September 5, 1934, to Howard and Rosalind (Wise) Biggs. She spent most of her childhood in Oregon with her brother, Bill. From a young age, Bonnie loved animals of all kinds and especially enjoyed riding horses. She graduated from high school in 1952 and soon began working with the ambulance crew as a dispatcher and driver, where she was in charge of 13 drivers. She remained extremely proud of this job throughout her life, as it was very uncommon in the 1950s for a woman to supervise men.

In 1956, Bonnie moved to California and began college. There she met Richard (Dick) Zebroski, and they were married on May 2, 1958 (later divorced in 1983). Five children were born to this marriage: Daniel, Steven, Caroline, Mary Lou, and Elizabeth. In 1961, Bonnie and Dick moved to the family ranch in South Dakota, where she raised their five children, helped with ranch chores, gardened flowers and vegetables, and cared for many animals. After the ranch was sold in 1972, the family moved to a small farm in Onida, where Bonnie lived until 1983.

Bonnie then moved to Pierre, South Dakota, where she worked for the state government as a proofreader and especially for Governor Janklow. She also worked at State Publishing. While in Pierre, she met her life partner, Thomas Piersol. In 1991, Bonnie and Tom moved to Keystone, South Dakota, where they purchased a home overlooking the old town of Hayward. She worked at various businesses throughout Keystone before becoming a rural mail carrier alongside Tom. They worked together until Bonnie retired in 2014 at the age of 80.

Bonnie lost Tom on January 3, 2022, a loss that left her deeply heartbroken. After his passing, she asked her daughter Liz to move in with her to help fulfill her wish of remaining in her home until the end of her life. Liz lovingly assisted with the upkeep and care of Bonnie’s property and home.

Bonnie volunteered many years of her time with the Red Cross, including assisting during Hurricane Katrina. She was a member of the Women’s Auxiliary of the Battle Creek Fire Department and was always eager to help anyone in need. Bonnie was known for being prepared for any emergency and for making sure everyone was well informed. She also loved volunteering with local museums to help preserve history for future generations. She served on the Keystone Schoolhouse Museum board and played an instrumental role in saving the museum.

Bonnie had an extensive collection of Indian artifacts, which she, Dick, and their children found over the years. She was especially proud to have this collection displayed at the High Plains Heritage Museum in Spearfish.

Bonnie loved her family deeply and was fortunate to see many great-grandchildren born, all of whom she was immensely proud of. She loved animals her entire life and could recite all of their names. Bonnie had a deep love of history and enjoyed sharing her knowledge with her grandchildren, great-grandchildren, and friends. She took great pride in her many flower gardens filled with roses, lilies, irises, and many other beautiful flowers. She also loved her rocks and Indian artifacts. One of her most treasured possessions was a large Madagascar jasper rock.

Bonnie will be deeply missed by her family and all who knew her. She is survived by her daughter Elizabeth (Liz) Zebroski, who lovingly cared for her until her passing, and her four other children. She is also survived by 10 grandchildren and 13 great-grandchildren, especially Molly, Brant, Delila, Lincoln Ager, Hayley Zebroski, Christian Standley, Andrea, Brody, Lainey Bauer, and Zachary Zebroski. Bonnie is also survived by her brother, Bill (Alice) Biggs, and numerous friends.

She was preceded in death by her life partner, Thomas Piersol; her mother, Rosalind; her father, Howard; and her aunts, uncles, and grandparents.