Donald Claude Thelen, Sr.

Donald “Don” Claude Thelen, Sr. of Manhattan, Montana passed away at the Bozeman Deaconess Hospital on March 12, 2022, after a debilitating stroke.

Don was born during a blizzard on March 18, 1933, in the family home, a 100-year-old farmhouse in Fond du Lac County, Wisconsin. He was the son of Peter Francis Thelen and Louise Thelma (Lyneis) Thelen. He attended James Otis School, a one-room rural grade school in Fond du Lac County. After graduating in 1950 from St Mary’s Springs High School in Fond du Lac, Don attended DeVry Technical Institute, launching his career in electronics. He applied his skills to advanced aviation electronics during four years’ service in the U.S. Air Force, a source of life-long pride to him. The Air Force stationed him across the southern United States and east Asia, most memorably Japan, Korea, and the Philippines. He rose to the rank of Staff Sergeant before honorably separating in 1956.

Don worked two years for AT&T in Wisconsin, then joined the Federal Aviation Administration as an electronics technician with responsibility for ground-based aviation electronics systems. He was an avid hobbyist pilot, earning multiple ratings and serving as a part-time flight instructor. He owned several airplanes during his life and enjoyed taking family and friends on flights that could include aerial stunts for willing passengers.

Working for the FAA enabled Don to continue his love of travel. His career took him across the northern United States (Wisconsin, Michigan, Wyoming, Alaska) before settling in Helena, Montana. During his employment he attended the University of the Air in Oklahoma City where he studied advanced aviation electronics, positioning him to troubleshoot complex problems and administer qualification exams to novice technicians. He retired from the FAA in 1989 after 30 years of service.

He continued his travels in retirement, splitting his time between Montana and Arizona for several years, often traveling in his RV, an interest that stretched back to the 1960s when he converted a school bus into a motor home. He had an adventurous spirit and a sharp technical mind.

Don was a Reserve Deputy Sheriff in Lewis and Clark County, Montana for six years and active in the Knights of Columbus, Elks, Masonic Lodge, and Algeria Shrine. He was an avid outdoorsman, enjoying hunting, fishing, camping, and motorcycling. He was a life member in the National Rifle Association, National Active and Retired Federal Employees, and Veterans of Foreign Wars. He was an active member of the Catholic Church.

Don married Mary Dolan on January 31, 1959, in Fond du Lac, Wisconsin; they divorced in 1978. They passed on their values of education, service, and love of the outdoors to their six children: Donald (Christina) Thelen, Jr. and Robert Thelen of Bozeman, Montana; Mary (Denis) Leonard of Northern Ireland; Louise (Paul) Uithoven of Bozeman; Joan (Tom) Brown of Lubbock, Texas; and Christine (Mike) Hedegaard of Northport, Alabama. He is survived by his children, ten grandchildren, one great-grandchild, sisters Catherine (Franklin) Birschbach and Genevieve (Glen) Stratz of Fond du Lac, and many nieces and nephews. He was preceded in death by his parents, sister Mary Frances (Louis) Wahoske, and his three brothers-in-law.

A funeral Mass will be celebrated at St John Vianney Catholic Church in Belgrade, Montana at 2:00 pm on March 18^th, the day Don would have turned 89 years old. Burial will be at the Montana State Veterans Cemetery at Fort Harrison, Montana, at a later date.