I assume the source of all that smoke was from the Whitewater fire as the valleys there seem to all point to Detroit, and it has to be the fire I was seeing from East Mtn.
So it looks like East Mountain is about 14 miles Northwest, as the crow flies, from where we watched the eclipse. We got to our spot the day before and observed both the Whitewater and the Detroit fires. The smoke wasn't really impacting us, since they were to the south and the wind was out of the Northwest. Then later in the afternoon heavy smoke moved in from the north. We talked to the county Sheriff, who happened to be out walking the trail, and checking the surrounding forest roads. He mentioned there was a new fire to the north of us, "up the '50" (road reference). Back at the trail head we saw a local fire crew turning up the road to find the fire. We drove up the road a couple miles and indeed saw thick blue gray smoke in the valley below the road and not that far to the north. Later parked back at the trail head a helicopter flew over head with a water drop, and shortly thereafter the smoke died down considerably, though it could have been a change in temps or wind. We opted to sleep in the back of the subi instead of backpacking just in case the fire moved or a new one arose nearby. No sooner had I fallen asleep then another officer rapped his flashlight on the car window and said the new fire had grown to 8 acres and we were likely fine but if the wind shifted we could be in a real bad spot. Discomforting to say the least. He said we didn't need to leave but that he wanted to warn us just in case and was putting up tape to close the road. After lying there awake for 15 minutes I hopped in the driver seat and moved us 2 miles in the other direction around a ridge and slept with the windows down to smell for smoke.
Next morning back at our spot the wind was out of the south and at that point it was a race against the clock between the rising and northward moving Whitewater fire smoke and the total eclipse at 10:19. Fortunately the eclipse won! and we had very clear skies overhead to the south and east, and were able to see a few stars at totality. I couldn't tell if the fire to the north had died down or if the wind was just blowing it north vs down on us, but from your pictures it looks like the smoke was just blowing north.
The sheriff mentioned that the new fire north of the Whitewater on Little Devil's Ridge was target shooters. We heard a good amount of target shooting all day and I can only assume that's what caused the fire to the north. Amazingly there was still shooting going on in that valley despite the new fire. At the risk of being too controversial I have ZERO use or tolerance for target shooting. Fires, noise pollution, trash...if someone can make an argument touting the merits of allowing target shooting I might listen...but probably not.
Picture of Jefferson pre-totality (as you can see it's completely obscured by smoke) and during totality (quite visible in the dark)
IMG_6784 by pauljess999, on Flickr
IMG_6806 by pauljess999, on Flickr
IMG_6831 by pauljess999, on Flickr
IMG_6979 by pauljess999, on Flickr
IMG_6611 by pauljess999, on Flickr
IMG_7003 by pauljess999, on Flickr
IMG_6570 by pauljess999, on Flickr
