This is Elderflower in bloom.  Sambucus canadensis.  This one is on Stonebriar across from the Nickleys' house.  
 

Elder is a native shrub with representatives throughout the United States. It is very common here in western NC and northeast GA.  As you're driving, you can see them with their large, white, flat-topped flower clusters.  Notice them now in bloom, then in August and September when they have set dark purple berries, you'll know what they are.  
 

Elderberries are edible, and medicinal.  An extract that helps prevent flu is often made from the berries.  Commercially, it is sold as sambucus, or elderberry syrup.  Some people make wine from the flowers;  never had that, but we do add the berries to our morning tea.  
 

I wouldn't suggest trying to harvest the berries from this tree though.  It's way down in the gully, looks snakey to me.  It's also important to consider WHERE a plant is growing when thinking about foraging.  Plants that grow near heavily travelled areas may be polluted by car exhaust, and plants growing on private property are not ours to forage.  So think about these things before collecting wild edibles.  Best to just look and admire in the wild, and appreciate them for their contribution to humanity.  And order your berries from Vitacost  https://www.vitacost.com// or Amazon.

HAPPY GARDENING!!!