U.S

Highway 16 Alternate from U.S. Highway 16 at Custer via Keystone to U.S. Highway 16. The state trunk highway system includes the following in Custer and Pennington counties: From a point on U.S. Highway 16 in Custer near the northeast corner of section twenty - six, township three south, range four east, thence easterly and northerly via Custer and Keystone to U.S. Highway 16 north of Keystone on the north line of section thirty - one, township one south, range six east. Source: SL 1984, ch 209 , § 12.