CR 523 begins at an intersection with Route 29 (Main Street) in Stockton, Hunterdon County, heading northeast on Stockton-Flemington Road through wooded residential areas. The road leaves Stockton for Delaware Township and enters a mix of farms and woods with some homes. The route intersects CR 605 before crossing CR 604 in the residential community of Sergeantsville. CR 523 passes through more rural areas as it comes to a brief concurrency with CR 579. After CR 579 splits to the south, the route enters Raritan Township and enters rural areas with increasing residential subdivisions. CR 523 intersects Route 12 at Dvoor's Circle and crosses into Flemington a short distance later, becoming municipally-maintained Mine Street, which is lined with homes. CR 523 turns north onto Park Avenue, passing more residences along with a few businesses. The route heads northeast on Walter E. Foran Boulevard, crossing back into Raritan Township. At this point, CR 523 resumes county maintenance and becomes a divided highway as it passes residential subdivisions, narrowing back into an undivided road as it turns east and intersects Route 31.