Grant County Oregon (Historic Districts) has 4 places on the National Register of Historic Places including 2 places of Statewide significance. Significant places include Cant, James, Ranch Historic District and Fremont Powerhouse, Sumpter Valley Railway Historic District, Sumpter Valley Railway, Middle Fork-John Day River.
Some of the country's most noteable architects helped create the Grant County places including Cress & Bisbee, E. W. Cummings and Joseph A. West. Prominent architectural styles found in Grant Country are Romanesque.