William E. "Bill" Kostner, age 80, of Mukwonago, WI (formerly Inver Grove Heights, MN), passed away on November 23, 2025, after a courageous two-month battle with pneumonia. Born on October 27, 1945, to Ervin and Lorraine (Soha) Kostner in St. Paul, MN, Bill was a devoted husband to Jan for 45 years, a loving father to daughters Julie and Katie, and a proud grandfather of five.

Bill graduated from Sibley High School in West St. Paul in 1963, where he excelled as a three-sport varsity athlete in football, hockey, and baseball. The first in his family to attend college, he earned his Bachelor’s Degree in Elementary Education from the University of Sioux Falls in 1972. A proud member of Delta Chi Epsilon, Bill spent decades joyfully organizing Homecoming gatherings and reunions for his cherished fraternity brothers.

Driven by a deep love for his country, Bill served in the U.S. Army as a clerk while stationed in Germany.  After returning to Sioux Falls, he married his beloved “wifey,” Janet Krause, on November 29, 1974.

Bill built a successful 32-year career with Valspar Paint Corporation, where colleagues and customers became lifelong friends. He was an active member in his church, supporting the men’s ministry and sharing his wife’s passion for children’s ministry.

He found great joy in the outdoors—spending more than forty years camping at his beloved Firefly Lake near Sayner, WI, and casting a line into the quiet waters of Dogskin Lake in Canada. Bill was also an avid sports fan, faithfully cheering on the Minnesota Golden Gophers, Vikings, and Twins every chance he got.

Bill shined as a girls’ softball coach. He was a dedicated mentor whose guidance, passion, and encouragement left a lasting mark on the field and in the lives of the young athletes he coached—an impact that will be felt for generations.

Above all, Bill’s deepest pride and happiness came from his family. He was immensely proud of his daughters and perhaps even more delighted by his grandchildren, eagerly sharing updates on their activities and accomplishments with anyone who would listen.

Bill leaves behind a legacy of faith, family, friendship, and patriotism. He will be deeply missed by all who knew and loved him.

Bill is survived by his daughters Julie (Tom) VanDixhorn of Birmingham, AL, and Katie (Andy) Sieberer of Elkhorn, WI; grandchildren Jake, Bailey, Abby, Drew, and Camryn; and niece Jackie Krause Johnson. He is preceded in death by his parents; his wife, Jan; brother-in-law Al Krause; nephew David Krause; and granddaughter Addy May Sieberer.

In lieu of flowers, the family requests that memorials in Bill’s name be made to the University of Sioux Falls Women’s Softball Scholarship or the Mayo Clinic Cancer Center and may be directed through the family.

A burial service and military honor will be held at Fort Snelling National Cemetery in St. Paul, MN, on January 9, 2026, at 1pm, followed by a reception at Southview Country Club in West St. Paul, from 2pm – 5pm, where we will gather to celebrate Bill and Jan’s lives and the love they shared.