SR 7 continues towards the well-developed eastern half of Loudoun County as a four-lane divided highway with some at-grade intersections, and it passes through Clarke's Gap in Catoctin Mountain. Another SR 7 Bus. splits off on the western side of the town of Leesburg, the county seat of Loudoun County. The main road continues as the Leesburg Bypass, and merges with the bypass of US 15 around the southern side of Leesburg, while the business route passes through town as Market Street. SR 7 Business intersects with US 15 Business (King Street) by the county courthouse in the center of Leesburg.