SDCL § 31-4-184: Interstate Highway 90 from Wyoming to Minnesota.

The state trunk highway system includes the following in Lawrence, Meade, Pennington, Jackson, Jones, Lyman, Brule, Aurora, Davison, Hanson, McCook, and Minnehaha counties:

From a point on the Wyoming state line west of Spearfish south of the northwest corner of section thirty, township seven north, range one east, thence easterly via Spearfish, Sturgis, Rapid City, Wall, Kadoka, Oacoma, Kimball, Mitchell, and Sioux Falls to the Minnesota state line east of Sioux Falls near the east quarter corner of section twenty-seven, township one hundred two north, range forty-seven west.