Highway 16 Alternate to State Highway 79. The state trunk highway system includes the following in Custer County: From a point on U.S. Highway 16 Alternate east of Custer near the east quarter corner of section twenty - four, township three south, range six east, northeasterly to State Highway 79 south of Hermosa near the southeast corner of section thirty - one, township two south, range eight east. Source: SL 1984, ch 209 , § 30.