The highway travels from U.S. Route 195 (US 195) in Colfax to a short concurrency with parent route SR 27 in Palouse before ending at the Idaho state line and becoming Idaho State Highway 6 (SH-6).

The highway turns south and east onto Echanove Avenue concurrent with SR 27, crossing a Washington State Department of Transportation (WSDOT) rail lube before turning south onto Division Street and splitting off.

[4] SH-6 continues east for 5.711 miles (9.191 km) along the Palouse River towards Potlatch, Idaho.

[5] Every year the WSDOT conducts a series of surveys on its highways in the state to measure traffic volume.

[6] A road connecting Colfax to Palouse and Potlatch, Idaho was first constructed in the early 20th century and appeared on a 1910 United States Geological Survey map of the Pullman area.