 The road begins at an at-grade interchange with CR 104 in the David Allen Sarnoff Pine Barrens Preservation Area, southwest of Flanders.It immediately curves from an east–west trajectory to a north–south one before its intersection with New York State Route 24 (NY 24).From that point on, the road becomes a semi-limited-access highway as it crosses the Peconic River before running through Riverhead Golf Course and crossing Sawmill Creek.