Jack M. Gantz

Jack M Gantz, 73, passed away peacefully at his home in Boise, Idaho, surrounded by family and friends, on August 11, 2025.

Born May 10, 1952, in Cascade, Idaho, to John and Shirley Gantz, Jack spent his youth hunting, fishing, riding motorcycles, building model airplanes, and exploring the outdoors he loved. He graduated from McCall-Donnelly High School in 1970, where he played basketball and served as student body president. Among his favorite early jobs was working on the trail crew at Big Creek.

In 1971, Jack enrolled in the drafting program at Boise State and began work as a draftsman for JUB Engineers while continuing his studies. He later transferred to the University of Idaho, graduating in 1980 with a degree in Civil Engineering. After graduation he worked for Montgomery Engineers and Forsgren Associates before taking a job with Idaho Department of Environmental Quality in 1993, retiring in 2017 after a long and meaningful career.

In 1973, Jack married his high school sweetheart, Karen Jarvis. Together they built a life filled with love, laughter, and adventure while raising their two children, Sara and Kyle. Jack cherished his role as a husband, father, and “Papa” to his grandchildren, delighting in teaching, sharing, and creating memories – whether making pancakes on a Saturday morning, coaching youth sports, building little free libraries for the community, or simply spending time together.

Jack was the very definition of a “jack of all trades.” He developed an interest in carpentry from his uncle during high school. He loved woodworking, home improvement projects, and he could fix anything. His garage was a reflection of who he was – always organized, tidy, and ready for the next project. Jack was a problem solver, and he faced life’s challenges – including his health struggles – with quiet strength and a great sense of humor. Never one to complain, he often reminded those around him with his favorite saying: “It is what it is.”

Jack was a proud Boise State fan, holding season tickets to football and basketball for many years. He loved traveling to see the Broncos play and cheering them on, whether in the stadium or on TV. He also cherished frequent trips to McCall and the Oregon Coast, enjoying the time spent with family and friends, whether it was fishing, exploring, or just relaxing together. He had a quick wit, steady patience, and a knack for knowing just what to do, which people always appreciated about him.

He was preceded in death by his parents, John and Shirley Gantz, and his brothers, Mike and Rob. Jack is survived by his wife of 52 years, Karen; his children, Sara Matson (Michael) and Kyle Gantz (Hailey); and three grandchildren, Adilynn and Tyler Matson, and Benjamin Gantz.

A celebration of Jack’s life will be held Wednesday, September 10, 2025, at 1:00 PM at Potomac Manor, located at 7311 Potomac Dr., Boise, ID 83704.

In lieu of flowers, memorial contributions may be made in Jack’s honor to the Boise State College of Engineering in support of the Annual Engineering & Science Festival, where he volunteered. Contributions may be designated to the Boise State University Foundation, NR039 – ESF 2026, and mailed to Boise State University Foundation, 1173 University Dr., Boise, ID 83706, or made by calling 208-426-2563.