Washington State Route 27

SR 27 southbound traveling into Tekoa under a trestle bridge carrying the John Wayne Pioneer Trail

SR 27 begins its 90-mile-long (145 km) route as Grand Avenue and part of the Palouse Scenic Byway at an intersection with US 195 south of Pullman.[3][4][5] The highway travels through downtown Pullman and becomes concurrent with SR 270 as it passes west of the Washington State University main campus.[6][7] Grand Avenue crosses the South Fork Palouse River and leaves the city of Pullman,[8] parallel to a Washington State Department of Transportation (WSDOT) rail line as it travels into the Palouse.[9] SR 27 travels northeast to the city of Palouse and crosses the Palouse River before a short concurrency with SR 272.[10][11] The highway continues northwest alongside the WSDOT rail line through the town of Garfield and Oakesdale before serving as the southern terminus of SR 271 west of Oakesdale Airport.[12][13][14] SR 27 travels northeast and crosses Hangman Creek into Tekoa as Crosby Street before it intersects SR 274, locally known as Poplar Street, at the north end of the city.[15][16] The highway turns west onto Poplar Street and travels under a bridge carrying the John Wayne Pioneer Trail before leaving Tekoa and Whitman County for Spokane County.[1][17][18]

SR 27 continues north along a Union Pacific rail line through Latah and Fairfield toward Rockford,[9][19][20] where it serves as the western terminus of SR 278 and the Palouse Scenic Byway ends.[4][5][21] The highway travels north out of the Palouse and to the Spokane Valley neighborhood of Opportunity,[22][23] and widens to four lanes as Pines Road. SR 27 intersects I-90 in a diamond interchange that utilizes Indiana Avenue and Montgomery Drive as exit ramps.[24] The highway continues north and crosses two rail lines, belonging to the Spokane International branch of Union Pacific and BNSF,[9] before the designation ends at Trent Avenue, signed as SR 290.[1][17]

Every year, WSDOT conducts a series of surveys on its highways in the state to measure traffic volume. This is expressed in terms of average annual daily traffic (AADT), which is a measure of traffic volume for any average day of the year. In 2011, WSDOT calculated that the busiest section of SR 27 was its interchange with I-90 in Spokane Valley, serving 27,000 vehicles, while the least busy section was between Tekoa and Latah, serving 640 vehicles.[25]

SR 27 was first codified as part of the Second Division of the Eastern Route of the Inland Empire Highway between Pullman and Oakesdale in 1913 and later became a paved branch of PSH 3 during the creation of the primary and secondary state highways in 1937.[26][27] The branch route traveled 68.71 miles (110.58 km) north from US 195 at the Idaho state border through Pullman and Oakesdale to PSH 3 and US 195 south of Rosalia.[28] SSH 3H was also established in 1937, traveling 38.69 miles (62.27 km) north from the PSH 3 branch in Oakesdale through the Palouse to PSH 2 and US 10 in Spokane Valley.[28][29][30] The two highways were combined to form SR 27 during the 1964 highway renumbering, part of a new state highway system still in place today.[31][32] A western bypass of Pullman for US 195 was originally planned in the late 1960s and was opened in 1974 as part of a proposed ring road around the city.[33][34] US 195 was routed onto the completed segment and SR 27 was extended south over its former route to intersect the new highway in 1975,[2] while the rest of the bypass would become the un-built SR 276.[35][36] The highway was extended north within Spokane Valley from its interchange with I-90 to Trent Avenue, signed as SR 290, in 1991.[37][38] The highway between Pullman and Tekoa was designated as part of the Palouse Scenic Byway on December 19, 2002, as part of the Washington State Scenic and Recreational Highways program.[39][40] The scenic byway was extended north in 2011 to SR 278 in Rockford.[5][41] A section of SR 27 near Spokane Valley was renamed the Sam Strahan Memorial Highway in 2017, honoring the lone victim of a school shooting at Freeman High School.[42]

• Highways of Washington State
• Palouse Scenic Byway