[9][10][11] US 195 enters Washington north of Clarkston in unincorporated Whitman County and travels west to an intersection with its 0.61-mile-long (0.98 km) spur route, providing a connection to US 95 northbound towards Moscow.

US 195 intersects SR 27, also part of the Palouse Scenic Byway,[10] and travels west of Pullman on a highway bypass of the city.

[13][14] The highway continues north along Pine Creek and the WSDOT rail line past the northern terminus of SR 271, a diamond interchange south of Rosalia,[15] before leaving the Palouse Scenic Byway at the Spokane County border.

The Second Division of the Eastern Route of the Inland Empire Highway was also established in 1913, traveling northwest from Sampson Trail Y at the Idaho–Washington state line to Pullman.

[28][29] The gap in the Second Division between Pullman and Colfax was named by Whitman County as a highway of importance the following year and was not built until 1925 as part of State Road 3.

[37] The section of US 195 between Spokane and Sandpoint became co-signed with an extension of US 2 from Bonners Ferry, Idaho to Everett, Washington in 1946,[38] and the highway was truncated to US 10 and US 395 in 1969.

[43][44][45] Funds that were originally intended for the canceled Bay Freeway project in Seattle were instead redirected to the bypasses earlier in the decade.

[43] US 95 was relocated onto its present freeway, bypassing Washington state, in 1977 and US 195 was extended south into Idaho to the new interchange with a spur route traveling towards northbound US 95.

[51][52] In 2002, WSDOT adopted a long range plan to upgrade US 195 within the Hangman Valley in Spokane to limited-access standards by constructing new interchanges at four intersections.

[54] Funding for the remaining interchange projects, estimated to cost $106 million in 2002 dollars, was not allocated and WSDOT is instead considering lower-cost improvements to the intersections.

[53][55] Increased traffic congestion on US 195 in Spokane lead to a development moratorium in place until capacity improvements are made to the highway.

[57] US 195 has a 0.54-mile-long (870 m) spur route near its southern terminus on the Washington–Idaho state line that travels east from US 195 to serve US 95 northbound atop Lewiston Hill.