The first impression I got when looking at the first few pictures was what we call 'hazel alder' - the scientific name is Alnus serrulata. They don't get too big, and you only find them growing by creeks. It might be one of the birches (the only birch I'm familiar with is river birch, but I don't think it's that one) or possibly witch hazel. I'd guess Alnus serrulata.

The last picture that the polyphemus moth is on looks like some type of oak, probably a white oak, but I can't tell for sure which one.

Sherry