Dr. Yubong Hahn

Dr. Yubong Hahn passed away peacefully on May 13, 2026, in Denver, Colorado, surrounded by the family he cherished. He was 83 years old. Born on October 26, 1942, in Seoul, South Korea, to Clarence Chi Chin Hahn and Bock Hee Chung, Yubong came into the world at a time of great upheaval - and met it, as he would meet everything, with fierce courage and an unshakeable sense of possibility.

As a child in Korea, his family endured the hardships of Japanese occupation and survived the devastation of the Korean War, yet he emerged a young man of exceptional drive. Like several of his siblings before him, Yubong earned the rare opportunity to pursue higher education in the United States. At just 17, he boarded a plane with horn-rimmed glasses and a single suitcase and set out to build a life on the other side of the world.

Yubong would go on to earn a Bachelor of Arts in Physics from West Virginia Wesleyan College, followed by a Master of Arts and a Ph.D. from the University of Missouri-Rolla. Between semesters in grad school, he met his wife, Myung, in Chicago, and they eventually settled in Boulder, Colorado, to raise their family and launch his company, RMI.

The mountains suited him perfectly. On any given weekend, he would load up his pickup truck with golf clubs and fishing gear and disappear into the hills, returning refreshed and sunburned (sunscreen was not his favorite). He loved the adventure and tranquility of the outdoors and passed that love onto his children with frequent ski trips and scenic drives through Rocky Mountain National Park.

Dr. Hahn is survived by his beloved wife, Myung Ok Hahn; his children, Steve and Denise; his grandchildren, Vale, Kitae, and Felix; his brother, Dr. Yu Kap Hahn; his sister, Priscilla Kyung Sook Lee; and many cherished nieces and nephews. He was preceded in death by his siblings Dr. Yu Hak Hahn, Young Sook Hahn, and Yu "Chin" Hahn.