for now, BIGTOOTH ASPEN (Populus grandidentata)
http://www.marylandbiodiversity.com/viewSpecies.php?species=1607
http://plants.usda.gov/java/largeImage?imageID=pogr4_002_ahp.tif
tree: http://plants.usda.gov/java/largeImage?imageID=pogr4_003_ahp.tif
and: https://gobotany.newenglandwild.org/species/populus/grandidentata/
leaf: http://newfs.s3.amazonaws.com/taxon-images-1000s1000/Salicaceae/populus-grandidentata-le-dkausen-b.jpg
dead leaves: http://newfs.s3.amazonaws.com/taxon-images-1000s1000/Salicaceae/populus-grandidentata-le-ahaines.jpg
another leaf: http://www.hubbardbrook.org/image_library/view.php?id=403
aspen leaf ID: http://www.google.com/search?tbm=isch&hl=en&source=hp&q=aspen+leaf+ID&btnG=Search+Images&gbv=1