U.S. Route 195 (US 195) is a north–south United States Highway, of which all but 0.65 miles of its 94.02 miles are within the state of Washington. The highway starts in rural Idaho north of the city of Lewiston as a state highway in an interchange with US 95. As the road crosses into Washington it becomes a state highway that connects communities in the Palouse region of Eastern Washington. US 195 travels north, serving the cities of Pullman, Colfax and Rosalia in Whitman County before continuing into Spokane County to its terminus in the city of Spokane at an interchange with Interstate 90 (I-90).

Lewiston is a city and the county seat of Nez Perce County, Idaho, United States, in the state's north central region. It is the third-largest city in the northern Idaho region, behind Post Falls and Coeur d'Alene, and the twelfth-largest in the state. Lewiston is the principal city of the Lewiston, ID-WA Metropolitan Statistical Area, which includes all of Nez Perce County and Asotin County, Washington. As of the 2020 census, the population of Lewiston was 34,203, up from 31,894 in 2010.