[3] The 1917 Mandan High School, designed by Gilbert R. Horton, was built to the east of the 1900 building and now sits on the northeast corner; its original, southern-facing entrance is now connected to a subsequent wing.

The 1966 addition is a comparatively small boiler room, attached to east (back) of the 1917 structure.

[3] 1976-77 addition designed by Ritterbush Associates provided classrooms for science, special education, and vocational studies in a one-story wing on the west side, and gymnasium attached to the northwest corner of the 1917 building.

Plans in 2017 were for the building to be renovated into 35 low-income housing units, utilizing Federal Historic Preservation Tax Credit funding which is opened by NRHP listing.

This article about a property in North Dakota on the National Register of Historic Places is a stub.