 By 1951, SH 118 had been incrementally extended south of Alpine to the park boundary along its present alignment through Study Butte and over the portion of the former spur road to the park boundary.State maintenance between Terlingua and Study Butte was reestablished as RM 2462 in 1956.RM 2462 was then extended westward to the Presidio County line just west of Lajitas in 1957.