Cheshire Cat! Clues 5 and 6

Okay, I just got my first comment on this puzzle, which I read too quickly before responding, and somewhat misinterpreted. Ron Schott wrote: "I'm gonna guess that the cinder cone that this lava flow emanated from is what's across the road, and the quarry was mining it for aggregate/road metal." Now I interpreted that to mean "The Cheshire Cat outcrop/quarry is a lava flow from the cinder cone," which is exactly the conclusion I was hoping someone might reach.  My response to Ron was "So far, so good. That's my assumption too- though without dating both, I can't say for sure. But it's consistent with everything I know and have seen in the area. And in fact, the next clue, which I'm aiming to get up before I leave, hopefully shortly, is to distinguish these two basalt components from the older altered rock in the area. But the question is, "What will we see when we cross the road from the quarry (other than Canal Creek)?" I'm betting you're close enough to figuring out the answer that if you look at some geographic names in the vicinity, you'll get it, along with the sequence of events." In fact, one of the things you will see across the road is a bit more of this flow, on the other side of Canal Creek. So Ron was, in a manner of speaking, correct, but there's still another thing that you'll see, on the same side of Canal Creek, below the road.

However, the shape of the "smile" in the original mosaic should be telling you something...

Here's a photo from Lava Butte, in central Oregon, that I was planning to put up in a day or two, if no one had made the cinder cone/lava flow connection:

Looking up the gutter of a lava flow from a later eruptive stage than that which formed the cinder cone, at Lava Butte, Newberry Volcano National Monument, Oregon. We'll call that clue 5. And here's clue 6: remember, most of the rock in the Quartzville area widely has been hydrothermally altered to one degree or another, and in this immediate area, we're pretty much at the center of the mineralization- the older, altered rock consists almost entirely of cross-cutting quartz veins and breccias. This is tough stuff. There are some joints and faults, but even these have largely been re-cemented with quartz.

 Vein quartz and crystals, near Red Heifer Pass, above Quartzville town site.

Roof (in quartz breccia) of the Snowstorm Tunnel, just uphill from the Quartzville town site.

And I'll toss in a couple reminders: look at the topo map of the area, and note names of features. (That link is framed a bit differently than the previous link in clue 3, and zoomed out by 2x- so it covers more of the general area.) Also, look over the road log, especially the stops after Yellowbottom, at mileage 22.0. If you do those things, the answer will be staring you in the face. I have a feeling if I have to post another clue, that one will be a dead give-away...