The architectural elaboration of this federal building emphasizes the importance of El Dorado to the region, and its prominence as a center for oil production. This handsome three-story Classical Revival building is nine bays wide with entrances one bay before each end of the facade. The entrances are each enriched with a columned portico carrying an entablature and small balcony from which paired Corinthian pilasters rise two stories to a pediment outlined with dentils. Other exterior decoration includes prominent keystones over the first story’s windows and swags over the upper windows, geometrically patterned aluminum grilles over entrance doors and some of the first-story windows, and a balustrade along the roofline. Elegant standing lamps flank each entrance. Inside, the post office occupies the first floor, and the courtrooms are above. The interior is richly finished with marble, fluted columns, and pilasters, and small circular tables are positioned along the center of the post office lobby.