This is Winter Falls, on the next drainage south from North Falls, so named due to the fact it's more of a steady drip than a waterfall by mid summer. There are at least two Columbia River Basalt flows, with the boundary visible as the recess through the upper middle of this view of the cliff. About halfway up from that is another boundary, but I'm suspicious that's a textural change within a single flow- from hackley jointing to columnar jointing, for example, rather than a third lava flow. Something I hadn't noticed until reviewing the photos, though, is that the upper portion of the lower flow and lower portion of the upper flow appear to have a pillow-like aspect to them... but I can't... quite... tell... at the best resolution of this shot. It's also at a spot where hikers are making a prolonged, steep climb, and all they can think about is "Get me to the top, now!" So not the best spot for thinking about what you're seeing, geologically. But if I ever get back here, pillow basalt is definitely something I'll seek evidence for or against in outcrops closer to the trail where I can get a better look at textures.
Another pretty pool on the hike from North Falls to Winter Falls at Silver Falls State Park. I quite possibly wouldn't have posted this one, but Anne liked yesterday's shot and sent me a couple links to relevant papers (both PDFs) on pool and riffle morphology. I haven't had time to look them over carefully (Honestly, I've just read the abstracts thus far.), but the first discusses how large woody debris (notice the lack of such in today's and yesterday's photos, compared to the left side of this one) influences characteristic pool spacing. The second involves an idea I hadn't heard before, "velocity reversals," but which makes intuitive sense to me. It's the idea that at low water, pools are lower velocity, but experience higher velocity than riffle areas during high water. This means that pools get scoured during high water, but riffles are depositional environments in those conditions. When the stream returns to a lower stage, it no longer has the competence to move the debris deposited in high water.
Photo unmodified. August 30, 2012. FlashEarth Location (pretty much guessing on this one too, but right general area).