SR 56 begins at an intersection with US 11 (Lee Highway) at Steeles Tavern a short distance east of the historic Cyrus McCormick Farm. The junction is just north of the Augusta-Rockbridge county line. SR 56 heads southeast into Rockbridge County as Tye River Turnpike, which enters George Washington National Forest and passes under Norfolk Southern Railway's Roanoke District at the village of Vesuvius. The state highway follows Little Marys Creek along its curvaceous ascent of the Blue Ridge Mountains. SR 56 intersects the Blue Ridge Parkway at Tye River Gap, where the highway enters Nelson County and becomes Crabtree Falls Highway. The state highway descends through Montebello and follows the South Fork of the Tye River past Crabtree Falls to Nash, where the highway begins to follow the Tye River proper.