Considered the oldest scenic highway in the U.S., this parkway runs through the Columbia River Gorge between Troutdale and The Dalles, Oregon. Built between 1913 and 1922, it has often been referred to as "the King of Roads" and compared with the great scenic roads of Europe, after which it was modeled. Significant for its engineering, which included early cliff-face road building, as well as for its rustic and naturalistic design, the road was largely the work of entrepreneur and Good Roads…