Hiking Olympic National Park By Erik Molvar Rainbow Canyon Nature Trail This trail is located at the Rainbow Day Use Area, a picnic ground near Walker Pass, 5 miles south of Quilcene on U.S. 101. The trail descends down forested slopes to reach an overlook of the Big Quilcene River. Here, the river flows through Rainbow Canyon, a steep-walled and heavily timbered defile through the foothills of the Olympic Mountains. The path soon seeks a side canyon, where Elbow Creek plummets over a small waterfall and into a quiet pool. The trail then continues its descent to reach the river, and emerges amid the alders along its course. Cliffs overgrown with vegetation guard the river as it arcs through a long curve.