Regarding the leg-wraps on the man in the photo, I just recently read about some hunters on the plains who had to endure a particularly cold winter, and they described wrapping their legs with feed sacks for warmth. I can't find the printed documentation now, but this photo of a buffalo hunter named Jesse Hendricks illustrates what they were talking about:
View attachment 191686
Yep, that's a Model 1874 Sharps (breechloader) and therefore unmentionable, but we're discussing the outfit. In any event, it's possible the leg wraps represent a serious attempt to use whatever was available to a fellow of limited means to keep warm.
I would go with the consensus here, that the image of the man in the original post probably dates to the very late 19th or early 20th century. As noted previously, we know a lot of people were still using muzzleloaders at that time. However, the caption of the stereoscopic card identifies the man "our mascot." I'm wondering if there might have been a crew or an expedition of some sort that brought this rag-tag fellow along to help out with menial tasks and provide some comic relief.
It's fun to speculate.
Notchy Bob