So, long story, the first version is actually a 3 shot +/- 1EV HDR merge and there were some artifacts from that process and these were exacerbated with the B/W rendering. So, in fact Isaac was right, but I was looking at the boundary between the white clouds and the black sky, not the darker clouds on the background of the lighter clouds where I think he was seeing this. So as to why do HDR, the answer is somewhat like the following: Why does a dog lick his balls? Because he can. Recognizing the limitations of a hand held HDR exposure, I went back to a single DNG and started the entire process from scratch. I am beginning to think like Eric, that HDR is unnecessary except in the most extreme circumstances, at least with my 800E. I believe the IQ in this version is superior to the OP; my imagination?
Anyhow, I took your suggestions to heart and repost the effort here. Went as far as I could in LR, only a bit of clarity applied, watching the clouds carefully: no visible artifacts to my eye. Darkened the foreground a la Slobodan but dodged some lighter spots so it looked kinda like spotty cloud shadows. Went to PS and after cloning out a couple hikers, applied a full contrast and structure filter with SEP2 to emphasize the rocks and to a lesser extent the clouds (masked that in the foreground and where it had screwed up the sky and was over the top with the clouds); I really wanted the SEP2 layer to bring out the luminosity in the rocks. Then I did the black and white conversion, bringing down the blue/cyan in the sky, but not as much as I did before; I see it as a dark gray now. Thanks Slobodan, I think it is less stark now. I also bumped up the yellows and reds in the B/W sliders to add more luminosity to the rocks against the darker sky/clouds. Finally, a high pass filter at 0.5 to avoid over sharpening of clouds and that was it. I have posted the B/W version of course; the color version is exactly the same with the B&W layer turned off.
Sorry for the lengthy technicalities, but your comments are helping me look at my images in much more detail and I wanted you to know I was paying attention