The state trunk highway system includes the following in Fall River, Custer, Pennington, Meade, Butte, and Harding counties:

(1) From a point on U.S. Highway 18 southeast of Hot Springs northerly via Rapid City to the intersection of U.S. Highway 16B;

(2) From a point on State Highway 34 east of Sturgis north to U.S. Highway 212 south of Newell;

(3) From a point on U.S. Highway 212 in Newell northerly to State Highway 20;

(4) From a point on State Highway 20 east of Buffalo north to the North Dakota state line.

Source: SL 1984, ch 209, § 51; SL 1986, ch 27, § 9; SL 1990, ch 225, § 1; SL 1994, ch 237, § 2; SL 2001, ch 157, § 2; SL 2005, ch 150, § 3.