What? Oregon’s Highway 138 (OR-138), widely known as the Highway of Waterfalls and designated along its core section as the Rogue-Umpqua Scenic Byway. The route tracks the North Umpqua River as it plunges from alpine volcanic high country down into deep, mossy temperate rainforest gorges filled with massive Douglas firs, giant ferns, rushing white water, natural cliffside hot springs, and more than 15 accessible waterfalls.