Probably juvenile anhinga:
That is possible. I also tried to look up some pictures and they could have been double crested cormorants?? Most pictures they appear more uniformly black but I also found some where they appeared more brown up top...
edit: I think they were probably anhingas - the sharp change in coloration from black to brown was definitely present... I have never heard of those birds before.
@birdman
We are in thermopolis wyoming and hiking to check out petroglyphs nearby. There were a bunch of birds living in circular domes on the cliff wall. Are those cliff swallows?
Very similar but were hanging under, and sandwiched all around each other, an overhanging rock ledge.
@birdman
Last day in Wyoming. We stopped at Sacagawea's gravesite. There was a bird with largely black feathers but the wing tips were white. Looked to be all business.
Also, saw four bald eagles (two a matting pair) along the snake river.
Maybe a black vulture?
I think it is pretty freakin great that when I was a kid Bald Eagles were very rare and I didn't see my first wild one until I was 19 on a trip to Florida, now they are literally everywhere.
Don't think so. Smaller. More... delicate.