The highway travels south for one mile (1.6 km) to the mouth of the Sand Hollow, where it intersects SR 243, which continues downriver to Mattawa and the Vernita Bridge.

[3] SR 26 turns southeast and travels up the barren Sand Hollow to the Royal Slope and its irrigated fields, situated between the Frenchman Hills to the north and the Saddle Mountains to the south.

SR 26 crosses into the Columbia National Wildlife Refuge in the foothills of the Saddle Mountains and enters Adams County near Tauhton.

[9][10] The highway continues to follow the railroad, now traveling along Willow Creek, and passes the town of La Crosse and its municipal airport.

[8] The highway crosses the river and travels through an industrial area before terminating at an intersection with US 195 on the north side of downtown Colfax.

[17][18] The highway is characterized as "dull and boring" by students, prompting towns along the route attempting to lure drivers with scenic guidebooks and posters.

[24][25] The state legislature reformed the highway system in 1937, adopting a new numbering scheme consisting of primary and secondary routes, and took over maintenance of roads using gas tax revenues.

[28] The remainder of modern-day SR 26, from Vantage to Washtucna, was little more than a collection of unpaved local roads that ran further north along Crab Creek.

[41] Another project added a left turn lane at a dangerous intersection between SR 26 and South Thacker Road west of Othello.

[44] Collisions on the highway, blamed partly on Washington State University traffic, have prompted new initiatives to improve its safety.

[45][46] SR 26 has a short spur route in Colfax that runs for 0.07 miles (0.11 km),[1] connecting the highway to the southbound lanes of US 195.