The state trunk highway system includes the following in Davison, Hanson, McCook, and Minnehaha counties. From a point on Interstate Highway 90 Business Loop in Mitchell, thence easterly via Mitchell, Salem, Montrose, Humboldt, and Hartford to a point on Marion Road in Sioux Falls.

Source: SL 1984, ch 209 , § 32; SL 1992, ch 202 , § 3; SL 1994, ch 237 , § 9; SL 1999, ch 147 , § 1; SL 2006, ch 155 , § 1.