Sweet Grass County Montana (Historic Districts) has 2 places on the National Register of Historic Places including 1 place of Statewide significance. Significant places include Brannin Ranch, Spannring, John Otto, Family Farm.
Some of the country's most noteable architects helped create the Sweet Grass County places including Barney Brannin and et al. Spannring. Prominent architectural styles found in Sweet Grass Country are Bungalow/Craftsman.