Re: Yellowstone or Wind River
How about going to 'Google Earth', zooming in and getting the overhead view of both places!
I recently did this and followed the Snake River from it's headwaters all the way to Idaho Falls, and The Henrys' Fork from Big Springs all the way to the confluence with the Snake.
*Comments posted above are only my opinion. I may be right....ehhh.....I'm certain they're wrong. Take 'em for what they're worth.*