Washburn-Crosby 'A' Mill Complex

Minneapolis, Minnesota

The “A” Mill was the largest flour mill in the world when it opened in 1880 (that is, until the rival Pillsbury family built their new mill directly across the river), and remained a key to Minneapolis’s milling prominence for decades to come; the company was later renamed General Mills. The “A” Mill operation shut down in 1965, and in 1991, a large fire gutted the building. But from these ashes rose the Mill City Museum, which opened in 2003 and is operated by the Minnesota Historical Society (MNHS).


The Washburn-Crosby “A” Mill Complex, including, Elevator #1, is a National Historic Landmark. Our work at the site has been ongoing; three projects are highlighted here.


Historic Structure Report. Our Historic Structure Report, included the museum building along with seven other structures on the site. MacDonald & Mack led the project team to investigate the history and existing conditions of the structures. The overall goal was to assist the Minnesota Historical Society in (1) understanding the history and evolution of the structures, individually and as an entire site, (2) ensuring long-term preservation of this important historic resource, and (3) planning for public interpretive programming and uses.


Elevator #1. A number of exterior elements of the structure had severely deteriorated and were posing a safety concern. The flat concrete roofs over the grain bins and Headhouse levels were unstable and the exterior bin walls were spalling in many places. Also, historic window and door openings were unsecured and unprotected, allowing birds and precipitation to enter the building, causing further deterioration.


We completed a comprehensive conditions assessment on the Elevator, followed by design for restoration. This included (1) replacement of the concrete roof over the grain bins; (2) repairs to the concrete Headhouse roofs; (3) major repairs (patching) of the exterior bin walls and Headhouse walls; (4) sealing of exterior window and door openings in the Headhouse.


The project required a high level of creativity from to accommodate the complex issues at this urban site. A significant challenge was the safe demolition and replacement of the bin roof at 100 feet above the ground.


Courtyard walls. MacDonald & Mack  completed a detailed investigation of the courtyard walls, identifying areas of significant deterioration, much of it previously unknown. Rehabilitation was recently completed.



Minnesota Historical Society



Mill City Museum

National Register nomination

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