SDCL § 31-4-237: State Highway 407 from Nebraska to U.S. Highway 18.

The state trunk highway system includes the following in Oglala Lakota County:

From a point on the Nebraska state line south of Pine Ridge near the northeast corner of section twenty-four, township thirty-five north, range forty-five west, thence north to U.S. Highway 18 in section twelve, township thirty-five north, range forty-five west.