The false-front, stepped parapet design of the Burnham building was once quite typical of downtown Moorhead commercial buildings. With later developments, and especially a major urban renewal project, the Burnham building is the only remaining example of its type in the city. It is in a basically unaltered state, though its setting has changed dramatically. Frank Burnham was an early Moorhead businessman and land dealer. He bought the 420 Main Avenue lot from the Lake Superior and Puget Sound Company, the townsite owners, and built the structure. He is thought to have had his office in the building until he sold it in 1884. Fire insurance maps from 1884 to 1929 show the building used only as a residence.

The 420 Main Avenue building is a detached commercial/residential structure dating from early in Moorhead's downtown development. The rectangular plan, two-story building, of frame construction and horizontal lap siding is often referred to as boomtown architecture. A stepped gable false front hides all but the eaves of a simple gable roof behind. The false front is marked by a frame cornice supported by small scroll brackets.

There are several, irregularly spaced, double sash windows on each side facade. The front facade second floor has two closely spaced double sash windows. The right side doorway is offset by a double wide window. The paneled door is surmounted by a transom window and an eyebrow arched door surround head. The green trim of the doors, windows, and cornice contrasts with the white commercial building. - MHPI, October 1979