James 'Jim' Vernon Dettmann, 87

James "Jim" Vernon Dettmann, 87, passed away Sept. 2, 2026, in Kalispell. He was born on July 1, 1939, in New Salem, North Dakota, the son of Clarence and Verna Dettmann. Jim’s family later moved to Harlowton where he played football, basketball, and dance before graduating high school.

Jim attended Montana State University, earning his Bachelor of Science degree in Chemical Engineering and the University of Oregon where he earned a Master of Science degree in Mathematics. He took a corporate job with Esso Research & Engineering Co. in New Jersey for a time but wanted to return to his beloved mountains in Montana. He obtained his teaching certification from Montana State University. He began his teaching career in Rudyard. 

During his time in Rudyard, he was awarded an Academic Year National Science Foundation Fellowship at the University of Oregon where he acquired his master's degree. For a short time, he took a job teaching at Hayward High School in California, finding it not to his liking and chose to return to Montana. Jim finally settled in Kalispell where he taught physics, chemistry, calculus & trigonometry at Flathead High School for 26 years. He also worked for the Forest Service and DNRC during the summer months as an aerial observer and a fireman on the Glacier View Ranger District.

“Mr. Dettmann” loved his teaching career and earned at least one “Teacher of the Year Award”. One of his favorite things about remaining in the Flathead Valley was occasionally running into one of his students who would stop and say, “Hi."

After retirement, Jim enjoyed his days to the fullest: hiking and cross-country skiing around Montana and in his favorite place, Glacier National Park. He loved all things nature, including the wildlife and plants. He also loved playing cribbage with his kids, jazz & big band music, dancing at the Eagles, watching basketball and football (GO CATS), reading, working crossword puzzles, German food, pie and cookies.

In 1969, Jim married Etta Webb, later divorced, and had two children, Mack and Katie.

Jim is preceded in death by his parents, Clarence and Verna Dettmann; his beloved companion, Shirley Astle; his brothers Alan and Larry Dettmann; and his son, Mack Dettmann.

Jim is survived by his sister, Linda Dettmann; his daughter Katie (Matt) Banks; [Mack] daughter in law Sheryl (Jordon) Dykstra; grandchildren Madison and Ainsley Dettmann, Emily (Jesse) Smith, Ethan (Sarah) Banks, Will (Sarah) Banks, and Elizabeth Banks; three great-grandchildren; two nieces and a nephew; and extended family.

Funeral services to be held at 2 p.m. on Oct. 4 at Darlington Cremation and Burial, located at 3408 Highway 2 E, Kalispell.

Family and friends gathering to follow. Feel free to show your Bobcat spirit by donning some blue and gold at the service.

In lieu of flowers, please consider donating to the Jim Dettmann Scholarship fund at Flathead High School, which is in the process of being established.