Where can I sit and not see the hand of man upon the country side?
Nowhere, unless you have no hands. Everywhere you go you will see human impact. That's what happens when you're human. Your last post, snough, is a bit disturbing. You have taken a simple discussion about the relationships between motorized and non-motorized backcountry recreationalists and turned it into a discussion on American society, commerce, religion, polotics, and philosphical perspective. Of course, I see your sarchasm, but it's not very effective.
For example: "The assholes should be able to do what ever they want."
As a matter of fact, yes, they can, so long as it does not impinge on the rights of other American citizens. This is one of the founding ideas of our country. It is one of the things people most appreciate about our country; and is a motivating factor for immigration. No, snowmobiling does not impinge on your rights to peace, solitude, and quite in the backcountry since you have many options to avoid the offending snowmobilers (as was mentioned in other posts).
Now, legalities aside, lets consider the "asshole's" perspective. He feels that he did nothing wrong, and probably sees YOU as an asshole for trying to spoil his idea of fun, recreation, and vacation. Think "Why can't these asshole BC skiers just get along with us or go to some area that we aren't allowed? Why do they feel that they have exclusive rights to the backcountry? We're just trying to have a good time, just like they are."
I agree that snowmobiles are loud and polluting. I too would like to see the manufacturers solve these issues, but unfortunately they will do nothing to that end unless it becomes mandatory or they see a financial gain to do so (not likely). Would you have the same opinion about the snowmobiles if they were not loud and polluting? Maybe we'll see electric snowmobiles in the future, but I doubt it will be anytime soon. So in the meantime, we'll just have to play where we can avoid that which we do not like.