Jefferson County Idaho has 6 places on the National Register of Historic Places including 3 places of Statewide significance. Significant places include Jefferson County Courthouse, Ririe A Pegram Truss Railroad Bridge and Ririe B Pegram Truss Railroad Bridge, Hotel Patrie and Jefferson County Courthouse.
Some of the country's most noteable architects helped create the Jefferson County places including Pregram. George H., Sundberg & Sundberg, Johnson J. Mickelson and Alexander Whitehead. Prominent architectural styles found in Jefferson Country are Art Deco and Colonial Revival.