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We are Mullen!

Mullen High School is a Lasallian, Catholic college preparatory school conducted in the tradition of the Christian Brothers to give a human and Christian education to the young, especially the poor, as established in our five Lasallian Core Principles.  Mullen belongs to one of the largest educational networks in the world. Lasallian schools educate more than 850,000 students in 80 different countries.


Mullen High School is named for John Kernan Mullen, famed businessman and 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 Bishop Henry Tihen, Mullen contacted Father Edward Flanagan, the founder of Boys’ Town, for advice on how best to design and operate such a school. Following Father Flanagan’s recommendation, Mr. Mullen wrote to an order of religious men working in Santa Fe, New Mexico and invited them to be the directors and teachers of his planned school – they were the Christian Brothers of St. John Baptist de La Salle. In June, 1928, Mullen opened negotiations with the De La Salle Christian Brothers. Unfortunately, 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 420-acre plot of land on the outskirts of Denver known as the Shirley Farms 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 that historic day, Mullen High School has experienced four distinct eras of change and growth:

List of 4 items.

  • The Orphanage Farm Years

    1931 – 1950
    When the school was conducted for orphan boys only, who both attended school and worked in the dairy farm.
  • The Boarding School Years

    1950 – 1965
    When paying boarders and day students joined the orphans as students and the school’s farm operations ended and its name was changed to J.K. Mullen High School.
  • The Boys’ High School Years

    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.
  • The Modern Years

    1989 – Present
    When the school became a co-educational high school and modernized its facilities and programs to become the campus and the school that today is Mullen High School!