When Flying they (US and Canadian IO) scan your passport. When driving not usually.
Why are you so concerned about returning home to the States? Unless you wanted there should be no problem.
The trick is getting back into Canada. As long as you are visiting you should be no problem. That means don't bring lots of stuff, have enough money to travel for length of stay, and reassure IO that you are going back to the States at the end of your visit.
Since you are so concerned. Let's say (for argument sake) they (US or Canadian IO) give you trouble. The longer you over-stay here the more likely Canada IO will give you trouble coming back. Again you are just a visitor.
Why are you so concerned about returning home to the States? Unless you wanted there should be no problem.
The trick is getting back into Canada. As long as you are visiting you should be no problem. That means don't bring lots of stuff, have enough money to travel for length of stay, and reassure IO that you are going back to the States at the end of your visit.
Since you are so concerned. Let's say (for argument sake) they (US or Canadian IO) give you trouble. The longer you over-stay here the more likely Canada IO will give you trouble coming back. Again you are just a visitor.