North of Gordonsville, US 15 expands to a four-lane divided highway that parallels the Washington Subdivision and the eastern flank of the Southwest Mountains, and passes Gordonsville Municipal Airport. The U.S. Highway becomes an undivided highway and passes the historic home Mayhurst at the southern limit of the town of Orange, where the highway becomes Caroline Street. US 15 meets SR 20 (Berry Hill Road) and runs concurrently with the state highway as a two-lane street under Norfolk Southern Railway's Washington District. SR 20 continues north on Caroline Street while the US 15 veers northeast onto four-lane Madison Road, which intersects SR 20 Business (Main Street) before leaving Orange as a two-lane road. US 15 crosses the Rapidan River into Madison County and meets the eastern end of SR 230 (Orange Road) at Madison Mills. The U.S. Highway passes through Five Forks, home of the Woodberry Forest School. North of Locust Dale, US 15 crosses the Robinson River and its tributary Crooked Run; at the latter stream, the U.S. Highway enters Culpeper County. The highway passes to the west of Cedar Mountain and meets the southern end of SR 299 (Madison Road) before reaching a diamond interchange with US 29 (James Monroe Highway), where US 15 Business continues north into the town of Culpeper.