Oregon I-84, about 25 miles east of Portland. First exit after Multnomah Falls, return west on old Columbia highway two miles, just past Horstail Falls.
Oneonta Gorge is a slot canyon just east of Multnomah Falls. Because of the massive log jam at the entrance, it doesn't see the presure other nearby places see. At the end of a half mile walk is wonderful falls that I was unable to reach due to deep water.
Moss covered slot canyon walls with waterfall in distance.