US 15 enters Maryland at Point of Rocks, named for the pair of mountain peaks between which the Potomac River cuts through Catoctin Mountain, Pine Rock in Maryland and Furnace Mountain in Loudoun County, Virginia. The highway crosses the river on the Point of Rocks Bridge, a two-lane, eight-span camelback truss bridge that also passes over the Chesapeake and Ohio Canal and CSX's Metropolitan Subdivision on the Maryland side of the river. Just north of the bridge, US 15 meets the western terminus of MD 28 (Clay Street), which serves as the main street of the community of Point of Rocks. The U.S. Highway heads north as a two-lane undivided controlled-access road that passes through a mix of farmland and forest on the eastern flank of Catoctin Mountain. North of its roundabout at MD 464 (Point of Rocks Road), US 15 has only two intersections, with Basford Road and Mountville Road, before passing under Elmer Derr Road and reaching a partial interchange with US 340 (Jefferson National Pike) east of Jefferson. There is no direct access from northbound US 15 to westbound US 340 or from eastbound US 340 to southbound US 15; that access is provided by using the Mt. Zion Road interchange to get turned around.