The highway then turns north and intersects Northeast 124th Street in a roundabout before entering Duvall, where it passes through downtown on Main Street. SR 203 continues northeast across the Cherry Valley and turns northwest before it reaches the Snohomish County line. The highway traverses the Tualco Valley and passes several farms, including one operated by the Monroe Correctional Complex, before crossing over the Skykomish River on a steel truss bridge at the city limits of Monroe. SR 203 travels through Monroe on Lewis Street, passing through residential neighborhoods and the west side of Al Borlin Park before reaching the city's downtown. The highway crosses Main Street and over the Scenic Subdivision of the BNSF Railway before SR 203 terminates at an intersection with US 2. Main Street continues north as Chain Lake Road, while US 2 continues east towards Stevens Pass and west to Snohomish and Everett. The junction is located east of the Evergreen State Fairgrounds and the terminus of SR 522.