Jack Lee Decker, 78, of Westcliffe, CO passed away Monday, July 14, 2025, surrounded by members of his loving family, after a courageous battle with glioblastoma brain cancer. Jack was kindhearted and thoughtful, cared deeply for his family and friends, and cherished each day God provided him.

Jack was born May 10, 1947 in Holton, KS, the son of W.L. "Bill" and Anna Belle (Littleton) Decker. One of three boys, he grew up working on the farm, playing sports of all kinds and participating in musicals and band in school. Jack graduated from Denison High School in 1965. He then graduated with a Bachelor of Science in Mathematics from Kansas State University, earned a Master's degree in Industrial Engineering from Lehigh University, and completed his doctorate coursework in Applied Mathematics at the Colorado School of Mines.

On August 30, 1966 Jack married the love of his life, Juanita Kay Porter in Denison, KS. Together they had one son and three grandchildren. Jack's devotion to Juanita was complete and enduring. Family and friends were the priority of Jack's life. He was ever present at the activities of his son, grandchildren and nieces/nephews. Jack truly invested in relationships, making many lifelong friends and could always be counted on to lend a helping hand. He was also the family historian tracing the family tree back for many generations.

In 2010, Jack retired after 26 years of teaching math and computer science at Washburn University in Topeka, KS. He began his work career in 1969 with Western Electric (AT&T) in Omaha, NE and spent over ten years working for Bell System companies in Nebraska, New Jersey, Missouri and Colorado. Jack treasured the many lifelong friendships that were developed during his time at Washburn and AT&T. Jack served faithfully as member, elder, and/or trustee for many churches during his lifetime, most recently as member of Community United Methodist Church in Westcliffe, CO.

Jack and Juanita loved to travel, especially with or to meet family and friends. They fell in love with the Rocky Mountains and made Colorado their home in retirement. Jack was kind, thoughtful, adventurous, hardworking, and fun-loving. He did not acknowledge the concept of idle time, making the most of each day. Jack enjoyed music festivals, flying (regaining his private pilot's license in his 70s), genealogy, golf and building or rebuilding just about anything (cars, tractors, planes).

Survivors include his wife, Juanita of the home; son, Brian Decker (Lisa) of Keller, TX; brother, Dick Decker (Susan) of Oskaloosa, KS; sister-in-law, Leann Decker of Holton, KS and three grandchildren, Annabelle Decker; Jacob Decker (Alana) and Olivia Decker. He was preceded in death by his parents and older brother, Jim Decker.

A Celebration of Life service will be held at 11:00am on Saturday, September 13, 2025 at Mercer Funeral Home in Holton. Burial will follow at the Denison Cemetery. Family will greet friends one hour prior to the service.

Memorials given in Jack's name can be sent to P.O. Box 270, Holton, KS  66436 and will support the American Cancer Society and the continuing education of students and faculty at Washburn University.