#1 looks like it might be hazelnut, which is native to the area, but it's a little hard to tell in this photo.
#2 looks like black walnut, which has golf-ball sized nuts which have a husk that is yellow on the tree, fall when ripe, and turn brownish-black
#3 is hard to tell from the photo, but maybe coffeeberry (Rhamnus californica)?
Location: Grass Valley, California (zone 9b)
posted 4 years ago
Again sorry for horrible pictures, but heres two others: