Lyle Kerstiens

Francis Lyle Kerstiens

If you are reading this, then you know that the soul of Lyle has departed this world for the next. Lyle was born December 7, 1950, in Colorado Springs and grew up in Simla, Colorado. His soul departed on August 28, 2026, at the age of 75.

He was predeceased by his parents, Frank and Marjorie Kerstiens; daughter Erica Kerstiens; and stepson Jonathan Garcia. He is survived by his beloved wife, Teresa; his son, Eron Kerstiens (Teri) of Los Alamos, NM; his stepdaughter, Jennifer Garcia (Lorenzo) of Rio Rancho, NM; sister Verna Gross (John) of Durango, CO; grandchildren Caleb Kerstiens, Jace Kerstiens, Anna Kerstiens, Kylee Elwell, Gavin Elwell, and Ashlyn Garcia; great-grandson Sebastian Garcia; and his very loyal dog, Ruby.

Lyle joined the Navy in 1971 and served on the USS James Monroe, SSBN 622, as a submarine reactor operator until 1978. He was extremely proud of earning his Dolphins, signifying “Qualified in Submarines” status, and loved telling sea stories. He belonged to the Veterans of Foreign Wars, American Legion, and United States Submarine Veterans. He didn’t have a PhD, but he did have a DD-214.

This nuclear background provided the experience to get hired at Los Alamos Scientific Laboratory, later known as Los Alamos National Laboratory. His LANL background included accelerator operations; quality assurance on plutonium reactor fuel processes, fusion reactor tritium fuel recovery, and high-level nuclear waste storage; I&C engineering on nuclear weapons underground testing; I&C engineering on high-explosive testing; computer and network management; facility software management; and the development and delivery of Conduct of Engineering training.

While working full-time, he managed to finish a Bachelor of Science in Electrical Engineering from the University of New Mexico and a Master of Arts in Organizational Management through the University of Phoenix. He was very proud of working at LANL and retired after 34 years. He continued to provide Conduct of Operations contract work for eight years when Teresa needed him to work with his own kind.

He liked any outdoor activity, including yard work. He took his children camping and backpacking in New Mexico and Colorado, where he and Eron managed to climb 34 of the 53 Colorado 14ers. He loved running mountains and canyons with his dogs, which morphed into marathons and triathlons, as well as skiing and snowshoeing. He designed and made much of his and Teresa’s furniture. Later in life, as his body parts wore out, he started playing bad golf.

He loved life and will be missed by all who crossed paths with him. He always worked to turn bad decisions into good ones and to repeat good decisions.

In lieu of flowers, his family requests contributions to Parkinson’s disease research.

Services to be determined.