During the American Revolutionary War, General Lafayette's division camped in what is now Oradell at Kinderkamack and Soldier Hill Roads.

Through the industrial area of the borough of Carlstadt, the four-lane highway, divided in some sections, is called Washington Avenue.

At the end of Moonachie Road, CR 503 then turns left onto the four-lane River Street, which passes under Interstate 80 and the New York, Susquehanna and Western Railway's New Jersey Subdivision line.

CR 503 then continues north through Oradell, Emerson, Westwood, Hillsdale, Woodcliff Lake, Park Ridge, and Montvale.

The northbound and southbound alignments split briefly in Montvale, where the highway again crosses the Pascack Valley Line one more time at Grand Avenue (CR 2).