This addition was completed in 1968 and dedicated in November of that year. It contains the south gallery, library, office, service rooms and corridors. Wall space in the library, vault and corridors, then provided space for uncrowded displays. After these artifacts and records of the County's earliest history some relics of the pioneer period. Farm activities such as building, butchering and going to mill are suggested by frow, woodplanes, square nails, hog scrapers, sausage stuffers and by stencils for marking grain sacks.
Cases contain Indian bead work, fine needlework, cameras and musical instruments.
A grouping of children's toys makes an attractive central display. County and community history, maps, and genealogical material may be used in the library. This gallery houses a variety of exhibits ranging from old telephone equipment to children's dishes. Many of the exhibits will be changed from time to time. To The Washington County Historical Museum brochure, Washington County Historical Association, 1997.