Mullen High School was named for John Kernan Mullen, businessman, philanthropist, and founder of the Colorado Milling and Elevator Company. Together with his wife, Catherine, Mullen envisioned the founding of a high school in Denver for orphaned boys. In 1928, working with Henry Tihen, Mullen contacted Edward Flanagan, the founder of Boys Town, for advice on how best to design and operate such a school. Following Flanagan’s recommendation, Mullen wrote to the Christian Brothers of St. John Baptist de La Salle in Santa Fe, New Mexico and invited them to be the directors and teachers of his planned school. In June 1928, Mullen opened negotiations with the De La Salle Christian Brothers. However, both Catherine and John Mullen died before the project could be completed, but their daughters and their husbands carried on with their plans. They purchased a plot of land on the outskirts of Denver known as the Shirley Farm Dairy. An agreement was made that would allow the dairy to remain in operation in exchange for the students’ opportunity to work in the dairy and receive training in agriculture and mechanics. And so, on April 8, 1932, 17 boys and three Brothers moved into the new J.K. Mullen Home for Boys. Since then, Mullen High School has experienced four distinct eras of change and growth:
1931–1950, when the school was conducted for orphan boys only, who both attended school and worked in the dairy farm;
1950–1965, when paying boarders and day students joined the orphans as students, the school’s farm operations ended and its name was changed to J.K. Mullen High School;
1966-1989, when the last of the orphans graduated, the boarding section closed, and the school became a four-year college preparatory high school for boys;
1989–present, when the school became a co-educational high school and modernized its facilities and programs.
Mullen enjoys an intense rivalry with Cherry Creek High School of Greenwood Village, Colorado. This rivalry was developed in the Centennial League and continues despite Mullen and Cherry Creek now play football in separate leagues since 2010. The two schools have met in the 5A State Football Championship game 3 times – 1998, 2004, and 2008, with Mullen winning each time. This rivalry is widely believed to be the state’s top high school rivalry and spans several sports and activities.
