CR 519 crosses into Green Township, Sussex County and becomes Hibler Road. A short distance past the county line, the route turns north onto Wintermute Road, which makes a turn northeast into a narrow agricultural valley. Upon intersecting CR 608, CR 519 enters Fredon Township and the name changes to Ridge Road. The road continues into a mix of woodland and residential areas, with some farm fields, before entering Newton. At this point, the route becomes West End Avenue and passes several homes. CR 519 comes to an intersection with Route 94, and turns east to follow that route along High Street. Route 94 and CR 519 continue to downtown Newton and come to the Park Place square, where the road meets US 206. At this point, all three routes run concurrent north on four-lane undivided Water Street for a short distance. CR 519 splits from US 206/Route 94 by turning northwest onto four-lane undivided Mill Street. The road soon narrows to two lanes as it passes businesses and makes a turn to the north, passing by Sussex County Community College.