John Koenig born September 6, 1933, in Boone, Iowa to Miles and Mary Koenig died September 4, 2020. John lived in many cities growing up due to his father's job with the railroad. He graduated from the University of Minnesota in Chemical Engineering in 1957.

He married the love of his life, Donna Schmitz, in Sparta, Wisconsin June 1957, and they moved to Idaho Falls to begin his career with Phillips Petroleum Company at Idaho National Lab. He retired from Argonne National Laboratory in 1992 with 25 years of service and numerous awards. He received his master's degree in Nuclear Engineering from the University of Idaho while working full time at Argonne.

During his retirement, he and his wife, Donna, spent their winters in Daytona Beach and Lake Havasu. John loved the outdoors. He enjoyed golfing, fishing, skiing, gardening, and backpacking. There were many great family vacations at Redfish Lake, Meadow Lake outside Gilmore, Idaho, camping throughout Idaho, and the National Parks.

Scholarships will be established in his name at the University of Minnesota and the University of Idaho.

John was preceded in death by his parents.

He is survived by his wife, Donna; his sons: David (Maureen) and Ken (Kris); his grandsons: Bridger, Mack, and Ryder; his brother, Edward; and his sister, Carol.

After 19 years of retirement, John developed Parkinson's and Dementia.

The family would like to thank the staff at Lincoln Court and Encompass Hospice for their wonderful care.

No services will be held. Cremation is under the direction of Coltrin Mortuary, 2100 First Street, Idaho Falls.