Williams County North Dakota has 10 places on the National Register of Historic Places including 4 places of National significance and 2 places of Statewide significance. Significant places include Fort Buford State Historic Site, Fort Union Trading Post National Historic Site, Fort Union Trading Post National Historic Site Historic District (Boundary Increase), Fort Union Trading Post National Historic Site Historic District (Boundary Increase) and Fort Union Trading Post National Historic Site Historic District (Boundary Increase).
Some of the country's most noteable architects helped create the Williams County places including American Fur Trading Co., Carl G. Steen, Joseph and Samuel DeRemer, W.W. Horton, J.G. Harding, Stacy-Judd, Robert Stacy Judd, R.S. Frost and Oscar Wenderoth. Prominent architectural styles found in Williams Country are Art Deco, Beaux Arts and Classical Revival.