Washington County Utah (Historic Districts) has 12 places on the National Register of Historic Places including 1 place of National significance and 5 places of Statewide significance. Significant places include Parunuweap Canyon Archeological District, Oak Creek Historic District, Pine Creek Residential Historic District, Santa Clara Hydroelectric Power Plants Historic District and Santa Clara Hydroelectric Power Plants Historic District.
Prehistoric cultural affiliation(s) include Virgin Anasazi, Southern Paiute and Western Anasazi dating back to 500.
Some of the country's most noteable architects helped create the Washington County places including unknown, Gilbert Stanley Underwood, NPS, Thomas C. Vint and Edward A. Nickel. Prominent architectural styles found in Washington Country are Bungalow/Craftsman, Greek Revival and Late Victorian.