DE 15 splits from DE 10 Alt. by turning north on Dundee Road, leaving Woodside. The road heads through a mix of farmland, woodland, and residential subdivisions, crossing Tidbury Creek before coming to a roundabout with DE 10. Past this intersection, the route becomes Moose Lodge Road and continues north. DE 15 turns east onto Westville Road and enters the town of Wyoming, where it becomes Southern Boulevard and passes homes and some businesses. The route turns northeast onto South Railroad Avenue and runs immediately to the west of the Delmarva Central Railroad. The road becomes North Railroad Avenue upon intersecting Grant Street west of the former Wyoming station before it leaves Wyoming as it crosses Isaac Branch to the east of Wyoming Lake. At this point, DE 15 becomes Wyoming Mill Road and heads north through agricultural areas away from the railroad tracks. The route has an intersection with Wyoming Mill Spur, which heads east to POW/MIA Parkway. The road continues through farmland with some woods and residential development before entering the city of Dover and curving to the northwest.