Under consideration for nearly twenty years, the College Union Building opened in 1952 to provide space for a much needed dining facility and a larger auditorium. North Union also afforded meeting and office space for student groups, many of which participated in raising funds for the building’s construction.
Upon its opening, Coconino County dedicated the building to the memory of Arizona State College at Flagstaff alumni who died serving in the U.S. military. From 1953 to 1967 North Union housed the campus bookstore. The second floor contained three apartments used to house visiting scholars, as well as the family of bookstore manager Joe Rolle.
Today, North Union continues to offer stage performances, movies, and game nights in Prochnow Auditorium. A snack bar known as the Timberline Inn has operated since the building's opening, and in 2011 the 1899 Bar & Grill opened in the space of the former dining hall. While offering a fine dining experience to the community of Flagstaff, the restaurant also provides hands-on experience for NAU students in Hotel and Restaurant Management.