Leaf formation on unknown tree: cocoon or something else?
Based on the location and assuming this isn't a domesticated hazelnut there are two likely hazelnut species.  The lack of the distinctive "beak" seen on the Beaked hazelnut means this is most likely an American hazelnut (Corylus americana):

The hairs along the young branch are also consistent with this (see for example the Plant Guide from the USDA).

Note, however, there are hybrids between American and European hazelnuts so it is beyond my ability to be completely sure by visual inspection alone.