As part of a general development plan, prepared in 1927, the Longmire Administration Building illustrates the maturing National Park Service philosophy of non-intrusive architecture in a glacial forest setting. Under the direction of Thomas C. Vint, chief architect of the National Park Service Landscape Engineering Division, his staff sought out design elements that would make the park buildings compatible with principles of unobtrusive construction in natural settings.

Considered the most architecturally important structure in Longmire, the Administration Building borrows design features from the 1924 Yosemite Administration Building, yet the materials used, heavy masonry on the first floor and a timber-framed second floor, create a unique connection to Mount Rainier.³⁰