 SR 100 is one of the major highways of the New River Valley, connecting Narrows and Pearisburg in Giles County with Dublin, Pulaski (via US 11), and Interstate 81 (I-81) in Pulaski County.SR 100 begins at an intersection with US 221 (Floyd Pike) at the eastern edge of the town of Hillsville.The state highway heads north as two-lane Sylvatus Smith Highway through northeastern Carroll County.