Those are great pics flipper!
I have a secret camping/fishing spot on the North Fork of the Lewis River that flows at the base of the south slope of Mt. St. Helens. This general area is known for multiple Bigfoot sightings. The forest there is all old-growth evergreens with lots of moss & ferns. In some spots, you can't see more than 5 feet off of the trail because the forest is so dense.
This was where I was camping when I heard similar howls/roars like you mentioned. (Slept with a scattergun close by that night.) My buddy & I walked by a tree about 10 yards from the camp that had a tuft of really long hair stuck to a branch about 6.5 feet off the ground. We grabbed it & checked it out. the hairs were about 7" long and were a dark auburn color. Cougar fur is not that long. Black bear fur could be, I suppose, and black bears come in various colors ranging from cinnamon-brown to jet-black, but the hair was a ways off the ground, in an awkward spot for a bear. Not far from that was a huge "bed" of flatened grass & wildflowers where it was clear that an enormous animal had bedded down at some point.
We always have at least two dogs with us when we go camping. There have been a couple of occasions 'round the campfire when the dogs will freak out and bark at something in the woods, but will be unwilling to actually go into the foods to investigate, which they do if it's a deer or something similar. In these cases, the dogs were frightened, whining, & stuck by us. Not saying it's Bigfoot necessarily, but it is strange & kinda scary.