SC 63 ALT: Appeared Feb 1938 (SCDOT) as a BELT route as a partial renumbering of SC 63 east of Islandton. For some reason it was routed in a sharp wedge instead of using all of the old SC 63 alignment.
In 1947, SC 63 ALT was downgraded to S-15-19. Today the N-S portion is S-15-84.