Roadside highway turnout with heritage marker Information sign of Fort Walla Walla. The site of a trading post that was erected in 1818, west of this point at the junction of the Columbia and Walla Walla Rivers. White Pass Scenic Byway - Lewis and Clark Trail This scenic highway has numerous campgrounds both state and private. There are many lodging opportunities along the way. From the junction of Interstate 5 to Naches is called the White Pass Scenic Byway. At Kennewick the highway joins the Lewis and Clark Historic Trail. The mountainous areas have many roadside turnouts with viewpoints where photographers will enjoy the vistas that await them.