SDCL § 31-4-185: Interstate Highway 90 Business Loops at Oacoma, Chamberlain, and Mitchell.

The state trunk highway system includes the following in Lyman, Brule, and Davison counties:

(1) From a point on Interstate Highway 90 at Oacoma, thence northeasterly via Oacoma and Chamberlain to State Highway 50;

(2) From a point on Interstate Highway 90 at Mitchell exit number 332, thence north to State Highway 38 and west via Mitchell to State Highway 37.