I would say that we're looking at the tree between the white pines. It seems to have compound pinnate leaves with 15 leaflets. That's not overly common. The first that come to mind are Mountain Ash (Sorbus spp)usually having 13- 19 leaflets and Ash (Fraxinus spp) trees which typically have 7-13 but can have 15 leaflets. Both types of trees regularly have the grey bark shown. If it has berries then Mountain Ash If keys are the seed
type then likely Ash. Though there are a few others, knowing where the pictures were taken would also help, along with a better picture of branch containing a few leafs.