L. Dean Duncan was born in Southern Illinois, on August 15,1927, the son of Elmer and Mary Edna Todd Duncan. As a small boy, Dean developed a passion for basketball and was seldom seen without a basketball in his hand either at home or at school. Dean was a junior guard on the 1944 Taylorville High School State Basketball Team. Dean enlisted in the Navy in 1945 and was assigned to play on the U.S. Navy Basketball team. He graduated from Centenary College in Louisiana with a bachelor's degree in Social Studies and earned a Masters and Doctorate Degree in Education from the University of Colorado, Boulder.
In 1956, Dean met the love of his life, Marlene at Fort Collins High School where they were both teaching. They taught together for 26 years. Dean spent 40 years teaching, coaching and mentoring students before and after graduation.
He was an avid athlete and climbed Long's Peak on is 75th birthday and skied the Rockies until the age of 85. Dean was the point guard on the Colorado Senior Olympic Team for several years.
Dean is survived by his wife Marlene, son Jim, daughter Jennifer, three beloved granddaughters, three great-grandsons, son-in-law Paul Gibson, six nieces and nephews (Cheryl Huggins of Taylorville), and several great-nieces and nephews. He was preceded in death by his parents, and two brothers James Luther and Elmer Otho Duncan.
A memorial service was held on Wednesday, February 20, 2019, at the Ft. Collins First United Methodist Church.