The highway, located entirely west of Spokane in the Inland Empire, serves Sprague, Edwall, Reardan, Springdale, Valley and Chewelah.
[1] Traveling northeast, the highway traverses a hill and cliff, passing Browns Lake, and turns west.
The roadway briefly turns east as Main Street before crossing a BNSF Railway line and continuing northeast alongside the tracks.
SR 231 turns north at Aspen Street and crosses the Eastern Washington Gateway Railroad and a marsh via a causeway.
[6] SR 231 crosses Sheep Creek and the same railway as Second Street and leaves Springdale, parallel to the railroad, into a valley.
[14][15] State Road 3 became PSH 3 during the same year and a secondary route, SSH 3J, was also established to span from the Little Falls Dam at Long Lake to Springdale.
[17][18] Three years later, the Spokane River Bridge at Long Lake Dam was constructed and spanned from the southern terminus of SSH 3J to Lincoln County.