Highway 18. The state trunk highway system includes the following in Oglala Lakota County: From a point on the Nebraska state line near the northwest corner of section twenty-four, township thirty-five north, range forty-two west, thence north to U.S. Highway 18 near the northeast corner of section two, township thirty-five north, range forty-two west. Source: SL 1984, ch 209 , § 109; SL 2015, ch 56 (HJR 1005), eff. May 1, 2015.