 The highway intersects Sandy Spring Lane (unsigned MD 15D) and crosses over the Maryland Midland Railway.US 15 leaves the town of Thurmont and meets MD 550 (Church Street) at a diamond interchange before crossing Owens Creek, which MD 550 follows up the mountain as Sabillasville Road.The U.S. Highway heads northeast through farmland and meets the northern end of MD 76 (Motters Station Road) before bisecting the campus of Mount St. Mary's University.