Great pics Terry. Two years ago when staying at Lake Powell Utah, I noticed the black streaks running down the face of the cliffs like in your pics.On my second cup at the moment, after which I should get up and go shave, put in the teeth, and get dressed.
I decided just now to do something I haven't done in some time and that is post some pictures. Dennis' comment prompted me to rub it in a bit. However, in all honesty, the following pictures were taken back in 2009 and thus, way before the need for face diapers.
Mesa Verde pictures.
Spruce Tree House area.
Perhaps of interest to some, such as myself, the cliff ruins also had other "rooms" off away from the main set of structures.
Cliff House
Hemenway House Ruins
Square Tower House Ruins
Balcony House area. Two or three structures here, one of which is somewhat destroyed.
Sun Point View area
Oak Tree House - Multiple structures on different levels of the cliff face.
I had wanted to go to Mesa Verde for years, but the one year prior when I had a fair opportunity to go, they were having fires in the area. I think one can see burned out trees in one of the photos above. Maybe more than one, but I'd have to look again. I was more interested in showing the different "house areas" than getting into details of what is there.
As a reminder, my photos are embedded in the forum in such a way that one can click on the image here at OSA and be directed to that photo on my Smugmug site. Then, clicking on the "X" towards the upper right, one can "exit" from the single image to where one can see the thumbnails in the rest of the gallery.
Never could get any answer from anyone that might actually know. Heard a lot of crude oil comments, but there is no drilling going on in that area in the past or projected into the future.