After percolating as groundwater, then emerging from springs to form Clear Lake, water in the McKenzie trough flows out of the lake, as the McKenzie River. More lava flows have created a number of waterfalls on the upper McKenzie. The first major one is Sahalie Falls, above. The interpretive signs at these day use parks do a nice job of clearly and simply explaining the setting here, as shown in the cropped photo below:
It's not easy (for me, at least) to read that at the scale presented here, but if you click to enlarge the photo, you'll find all the locations I've commented on over the last few days are labeled. From upstream/north to downstream/south these include Lava Lake, Nash Crater, Fish Lake, Sand Mountain Cones, Clear Lake, and Sahalie Falls. Hayrick Butte, mentioned in Monday's Clear Lake Addendum, is a bit west (up, on the map) from Hoodoo Butte.
Photo unmodified. October 9, 2012. FlashEarth Location- cross hairs on parking area, falls clearly visible to the northwest.