Custer County Idaho (Historic Districts) has 7 places on the National Register of Historic Places including 4 places of Statewide significance. Significant places include Challis Archeological Spring District, Challis Brewery Historic District, Custer Historic District and Idaho Rocky Mountain Club and Idaho Rocky Mountain Club.
Prehistoric cultural affiliation(s) include Archaic, Paleo Indian, Late Prehistoric, Late Archaic and Historic-Aboriginal dating back to 7999 BC.
Some of the country's most noteable architects helped create the Custer County places including Ellis Bjorling. Prominent architectural styles found in Custer Country are .