After the enthusiastic response to the last time I posed arboreally inclined questions here, I am inclined to crowdsource answers again. (Last time it was an immature Sitka Spruce, or Picea sitchensis.)
Can anyone name this tree? It was growing near Pemberton but by no means is it native. I have an idea what it might be. It is a tricky one. And the only clue is a leaf.
Eat Logical Sentences 
Platanus racemosa?
I don’t think it is a sycamore tree because the leaves are all began red and have stayed that colour… definitely the right size and shape though.
Acer (Maple) genus. Couldn’t tell you the species. It’s ornamental, I’d guess. Sycamores etc can be distinguished from the Maple as their venation does not converge i.e. all Maple veins, like little tributaries, arrive at the stem at the same time. Other Maple-like species tend not to converge that way; a vein will run into another (again, like tributaries) and the larger ones will converge at the stem.
Lots and lots of ornamental Maples around. The one in the background is probably an Ash or something: compound (?) leaves: http://treedoctor.anr.msu.edu/ash/ashtree_id.html
I think it is a Norway Maple (Acer platanoides). Both Doug and Joel correctly surmised it was a cultivar of Maple. It seems to be a cultivar that produces reddish-purple leaves rather than green ones. Most likely either “Crimson King” or “Schwedleri“.
Of course, I don’t really know…