Ok, I am biased. I think Michigan in the fall is the most spectacular place ever. Of course, those of you in other states might argue, but this is MY story and I'm sticking to it!
And to indulge in my geekness, just WHY do leaves change color??
The National Weather Service says it's because the earth is tilting away from the sun (for us in the northern hemisphere). This causes less intense sun and heat so the leaves stop their food making process and the green chlorophyll breaks down allowing the actual leaf pigments to show in all their glory. Different types of trees have different colored leaf pigments.
I sure wish my big maples had some of that red pigment!! Stunning! We just have yellow and a case of nasty black spot.
source 2 - has a bunch of links to more pictures!!