Mitchell Hall

Added by Rebecca Casbon Salgado, last update: August 17, 2012, 12:05 pm

Mitchell Hall
Exterior View of Mitchell Hall, looking southeast, source: USAFA McDermott Library archives
Intersection of Faculty Drive and Fairchild Drive UTM References: Zone 13, Easting 509295, Northing 4317840
Colorado Springs, CO 11375
United States
39° 0' 23.8032" N, 104° 53' 13.2396" W
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Identity of Building / Site
Primary classification: Education (EDC)
Secondary classification: Administration (ADM)
Federal, State, or Local Designation(s) and Date(s):

1993: Cadet Area (which Mitchell Hall is part of) becomes eligible for National Register listing
April 1, 2004: Cadet Area is listed as a National Historic Landmark District

History of Building/Site
Original Brief:

The U.S. federal government established the Air Force as an independent branch of the military in 1947, and authorized the creation of the U.S. Air Force Academy in 1954. The USAFA was meant to be the main undergraduate university for the Air Force, similar to West Point in New York and the U.S. Naval Academy in Maryland. At the time that the USAFA was planned and constructed, the United States had already entered into the Cold War with the Soviet Union, and the Air Force was seen as the most important arm of the military for this conflict. As a result, the Air Force grew quickly, and many new Air Force officers were needed. The USAFA provided education to young men who would ideally become these new officers.

The U.S. Air Force Academy is located along the Rampart Range of Colorado, a scenic natural area made up of forested hills and valleys along the base of the Rocky Mountains. The Cadet Area occupies the highest ridge of the USAFA campus, and has a soaring view toward the open plains to the east of Rampart Range. Mitchell Hall, the USAFA dining hall, is part of the original master plan for the Cadet Area of the Air Force Academy, and is located off the main campus plaza, the Terazzo, along with other significant cadet buildings such as dormitories and academic buildings.

SOM was commissioned to build a dining hall that could seat all of the cadets (3,000 at that time) at once and feed them quickly, since the cadets' daily schedule is very regimented. The SOM design team, led by Gertrude Lempp Kerbis, wanted to make the dining hall’s interior column-free, and developed an advanced roof of steel trusses supported by sixteen perimeter columns to make this possible. SOM had initially wanted to have glass curtain walls on all four sides of the building to allow for maximum views of the surrounding site, and to have the food-preparation area on the floor below the dining area with small elevators to bring food up, but this would not allow the food to be served fast enough, and so they ended up designing the building so the main kitchen area was on the same floor as the dining area.

Dates: Commission / Completion:July 23, 1954: SOM is chosen to be the architects of the USAFA, following interviews of several firms by a special selection board. July 1954 to May 1955: SOM develops the design for the USAFA, culminating in an exhibition of the campus plan at the Colorado Springs Fine Arts Center in May 1955. January 6, 1958: Mitchell Hall's massive roof is lifted into place as one single piece. September 1958: The first class of cadets occupies the Cadet Area.
Architectural and other Designer(s): architect: Gertrude Lempp Kerbis of SOM (project architect) landscape/garden designer: Dan Kiley designed the Terrazzo in 1959, directly to the north of Mitchell Hall other designers: Walter Netsch Jr. and Gordon Bunshaft, SOM design managers for the USAFA consulting engineer: American Bridge Division of the U.S. Steel Corporation building contractors: Air Force Academy Construction Agency (formed especially for the construction of the Academy, and disbanded after its initial completion); American Bridge Division of the U.S. Steel Corporation (fabrication and erection of roof); Vagtborg Lift Slab Corporation (lifting of roof)
Others associated with Building/Site: name: Brigadier General William “Billy” Mitchell association: namesake of Mitchell Hall events: Mitchell was an early U.S. military aviator, leading several successful air battles during World War I, where he was in charge of more than a thousand American and Allied airplanes. Mitchell was an early advocate for an independent U.S. air force, but was very outspoken in his opinion that air warfare was not being given enough attention, leading to him being court marshaled and convicted of insubordination. In 1926, he resigned from the military, but he was awarded the Congressional Medal of Honor posthumously in 1946 and is recognized today as an early aviation hero. names: Eero Saarinen, Wallace K. Harrison, Welton Becket, and Pietro Belluschi association: Members of the federally appointed architectural advisory committee for the Academy events: The committee asked questions of and gave suggestions to SOM in the course of the planning of the USAFA
Significant Alteration(s) with Date(s): 1966: The number of Cadets attending the Academy increased from around 3,000 maximum when it opened to around 4,000 by the late 1960s. As a result, Mitchell Hall was expanded on its east and west sides, partially blocking the openness of the space and views to the mountains when support columns were added. The architecture firms that were in charge of this renovation were Leo A. Daly and Henningson, Durham, and Richardson.
Current Use: The Cadet Area’s appearance and function have changed very little since the Academy first opened in 1958, which is a testament to the foresight of SOM’s design team when they were planning the campus and the consistency of the USAFA’s mission. Although the number of cadets attending the Academy has grown since it first opened, Mitchell Hall is still able to serve all of them at once during mealtimes, which was the main requirement for the building when it was designed.
Current Condition: The Air Force Academy was meant to be a monument from its initial design phase, and the campus's integrity has been well maintained as a result. Mitchell Hall was expanded on its eastern and western sides in 1966, eight years after it was first opened, but otherwise has kept many of its original interior and exterior features. While the Cadet Area and Mitchell Hall have been well preserved on the whole, additions were made to the campus in the late 1960s and early 1980s that SOM felt didn’t fit with their overall design for the USAFA. As a result, in 1985, SOM developed a master plan for future development of the Cadet Area to prepare for further expansions or alterations. This plan was updated by the USAFA Design Standards, developed by SOM in 2001, which are continually updated by the firm. Also, although the USAFA site is around 17,500 acres, it is now surrounded on all sides by increasing development of Colorado Springs, which has doubled in size since the Academy was first built. The Academy’s planners were prescient in requesting such a large site for the Academy, but the federal government could possible choose to sell off part of the Academy’s land in the future, which would greatly affect the character of the USAFA.
General Description:

Mitchell Hall is a two-level building that is a 308-foot-by-308-foot square in plan. It has a flat roof with a twenty-one-foot cantilevered overhang on all four sides. The roof is described in more detail in the technical evaluation of this fiche. Cadets enter Mitchell Hall in formation through two fifty-six-foot-wide entrances that face the Terrazzo. Mitchell Hall only appears to be one story high from the Terrazzo, which is immediately north of the building, but its site slopes dramatically downward so that the dining hall’s southern facade is the equivalent of almost three stories below the Terrazzo entrances. The top floor contains the main dining area and kitchen serving space, as well as a mezzanine level along its northern side for higher-ranking Academy staff and guests above the kitchen service area. The bottom floor, eighteen feet below the dining level, has loading docks on the building's east facade and contains freezers, food storage, and employee workspaces. In addition, the bottom floor houses a more formal dining room for special events.

Similar to the other SOM-designed buildings in the Cadet Area, Mitchell Hall's exterior material palette consists of steel structural elements, aluminum detailing and window frames, and gray-tinted plate-glass walls on all sides except for the northern facade, which is finished with exposed-aggregate precast-concrete panels. While the structure for the upper level is steel, the lower level's structure is reinforced concrete. SOM wanted to provide as many views to the outside as possible for the dining hall, although the glass at the USAFA is mostly tinted because of the bright Colorado sun. The interior of the main dining hall space is one open room with a twenty-four-foot-high, coffered-camp ceiling with fourteen-foot-square panels. The dining area's floor is polished brown terrazzo divided by a grid of aluminum strips that continues from the Terazzo floor outside of Mitchell Hall into the building. The stairway leading to the mezzanine level of the main dining area has white marble treads and a black steel railing, and the floor of the mezannine level is white polished terrazzo.

Mitchell Hall was designed to fit the functional requirement of feeding thousands of Cadets at once while also reflecting the forward-thinking spirit that the Air Force, the military's newest branch, wanted to project to the world. The USAFA's architectural characteristics—clean forms, often raised from the ground, clad in steel, glass, and aluminum—shared similarities with the Air Force's airplanes, and set the USAFA apart from the architecture of West Point and the U.S. Naval Academy.

Construction Period:


Original Physical Context:

The Cadet Area is sited on the Rampart Range along the base of the Rocky Mountains. Before the USAFA was built, the land it occupies was undeveloped, and consisted of a series of partially forested ridges and valleys. The Cadet Area sits atop the highest ridge on the property, and required the construction of more than ten thousand linear feet of concrete-and-stone retaining walls to give the cadets a flat plaza, the Terrazzo, around which the other main university buildings (including Mitchell Hall) are sited.

Technical Evaluation:

Mitchell Hall's steel-truss roof, with a clear span of 266 feet square, was the first long-span steel structure to be lifted into place, all in one piece. The roof's twenty-three Warren trusses were mostly prefabricated, but still required twenty-seven welders on-site for the final installation. Each joint of the trusses was welded for added strength, and each element had to be calculated separately, leading SOM to use some of the earliest structural-analysis computer programs. The trusses range in depth from eight-and-a-half feet to more than eleven-and-a-half feet. Once the 1,150-ton roof was assembled on the ground, it took just six hours for hydraulic jacks to lift it into place atop sixteen supporting columns.

Also significant is Gertrude Lempp Kerbis's decision to have the trusses cantilever out twenty-one feet from the dining hall's exterior walls. This allows the trusses to have a cleaner structural appearance since the cantilever keeps the roof from sagging in the center, removing the requirement for extra bracing around the interior perimeter of Mitchell Hall's roof. This overhang also gives the cadets some shelter as they march in formation into the dining hall.


Mitchell Hall is socially significant as an early example of a high-profile project whose design was headed by a woman architect, Gertrude Lempp Kerbis of SOM. Kerbis studied with Mies van der Rohe at the Illinois Institute of Technology, graduating from there in 1954 with a Master's in Architecture. That same year, she was hired by SOM. On July 23, 1954, the firm won the commission for the USAFA, and Kerbis was assigned to be in charge of the design of the Academy's dining hall. Although Kerbis designed the innovative truss roof for Mitchell Hall, she was excluded from seeing the roof being lifted into place, and was not allowed to take part in presentations to the project clients. In 1967, Kerbis founded her own firm, Lempp Kerbis Associates, which remains in operation to this day, and she also has worked throughout her career to secure equal working conditions for women in the architecture field.

Cultural & Aesthetic:
The Air Force Academy is an important early example of modernist federal architecture in the United States. Today, the USAFA's Cadet Area is recognized by architectural historians as one of the most significant groupings of structures built after World War II in the United States. The design and construction of the USAFA was followed by people all over the country, and congressional hearings were held several times to discuss its progress. Today, the USAFA is a top tourist site in Colorado, where visitors can enter the Cadet Chapel and even see the Cadets march in formation into Mitchell Hall for meals several times a week.

The U.S. Air Force Academy has historical significance as one of the three service academies for the U.S. military, along with West Point and the U.S. Naval Academy. The USAFA was constructed for the Air Force little more than a decade after the branch was officially formed, and was built in the context of the Cold War, for which the Air Force was seen as a key component to defeating the Soviet Union. The USAFA gave the Air Force a state-of-the-art training facility for future officers, and serves a crucial role in military operations to this day.

General Assessment:
From its initial planning and design, the USAFA was intended to become a national landmark, and it has stayed true to this mission to this day. It served as a strong symbol of the recently formed Air Force at a time when the strength of this branch was crucial to the United States' Cold Mar military strategy. Mitchell Hall is a contributing building to the overall Cadet Area, and is significant as a part of this larger group. Beyond being a component of the Cadet Area, Mitchell Hall is an important modernist building in its own right because it is a structurally advanced space designed by a pioneering woman architect, Gertrude Lempp Kerbis, who was part of one of the most influential firms of the twentieth century, Skidmore, Owings and Merrill.
Text references:

“The Air Age Acropolis,” Architectural Forum 10 (June 1959): 158–65; Carter, Karen, filmmaker, “Gertrude Lempp Kerbis, Modern Architect—part 2,” AIA Chicago (2008), accessed online at; Chicago Architects Oral History Project, “Gertrude Kerbis, Biographical Summary,” website of the Art Institute of Chicago, Hosington, Daniel J., "National Historic Landmark Nomination: United States Air Force Academy, Cadet Area" (United States Department of the Interior, National Park Service, June 2, 2003); Kerbis, Gertrude, “Oral History of Gertrude Kerbis,” interview by Betty J. Blum, Chicago Architects Oral History Project (Chicago: The Art Institute of Chicago, 1997), ISBN 978-0226076935; King, Susan F., filmmaker, “Excerpt 3,” filmed as part of the Chicago Architects Oral History Project (Sept. 11, 2006), accessed online at Nauman, Robert Allan, On the Wings of Modernism: The United States Air Force Academy (Chicago: University of Illinois Press, 2004), ISBN 978-0252028915; ———, “Preserving a Monument: The United States Air Force Academy,” Future Anterior 1, no. 2 (Fall 2004): 32–41; Olsen, Sheri, "Raising the Roof: The Dramatic Construction of Mitchell Hall," in Modernism at Mid-Century: The Architecture of the United States Air Force Academy, ed. Robert Bruegmann (Chicago: University of Chicago Press, 1994), 74–75; “The United States Air Force Academy,” Architectural Forum (June 1955): 102–10; U.S. Air Force Fact Sheet, “Brig. Gen. William ‘Billy’ Mitchell,” website of the National Museum of the U.S. Air Force,; U.S. Air Force Fact Sheet, “Mitchell Hall,” website of the U.S. Air Force Academy,

Recorder/Date: Rebecca Salgado, Columbia University, February 2011
Additional Images
Mitchell Hall
Interior of Mitchell Hall during the cadets' lunchtime, Source: Jon Casbon, date: Feb. 2, 2011
Audio and Video Web References

Depicted item: 2008 Interview with Gertrude Lempp Kerbis discussing Mitchell Hall, source: YouTube, part 2 of a film by Karen Carter commissioned by the Chicago Branch of the AIA in recognition of Kerbis's AIA Lifetime Achievement Award
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