This thematic study includes twelve post offices owned and administered by the U.S. Postal Service (USPS) throughout the State of Wyoming. These include the Basin, Greybull, Douglas, Lander, Torrington, Thermopolis, Buffalo, Kemmerer, Powell, Yellowstone, Evanston, and Newcastle Main Post Offices.

The buildings represent a continuum of federally constructed post offices allocated to the state between the turn of the century and 1941. The buildings exhibit a variety of styles and sizes but maintain a common demeanor representative of the federal presence. All of the buildings were constructed from standardized plans developed from guidelines provided by the Office of the Supervising Architect in the Treasury Department.

Variations in design styles reflect both the transition in the design philosophies of the Supervising Architect and the requirements developed in response to the Depression. These variations in design, as well as functions are also somewhat related to the communities in which they were placed and reflect the economic, political, and governmental context of those communities.

Located near the center of the town of Basin opposite the town's courthouse square, the Basin Republican-Rustler Building is a plain one story rectangular masonry and frame structure. Architecturally, the building is not unusually significant. At the time of its nomination to the National Register of Historic Places, the Basin Republican-Rustler Building was important for its contents, an ensemble of antique printing machinery and equipment. It was also important for its association with the Rustler, a Wyoming newspaper that was, in 1889, the first to be published in the Big Horn Basin.

The building was also the home of the Republican which was begun in 1905 when the Rustler became democratic in its political affiliation. The weekly paper became the Basin Republican-Rustler in 1928. The relationship of the building to the newspaper industry is particularly important because both the Republican and the Rustler individually, and combined as one paper, played a role in the settlement and development of the Big Horn Basin.