Trying to identify two trees

Today at Peebles Island, there were two trees that I tried to identify. As I found when I tried to identify trees last summer, mostly I can't figure out what trees are when I try to identify them.  But somehow in time, I got to know what many of the trees I see were, so maybe in time, I will come to realize what these are too.  The way it works is I study the trees, I study the books, and at first there is no connection between books and reality, but then all of a sudden, I find I know the name of a tree I've been seeing for a while.  I think it's good that way.  I think it would feel like cheating if someone just told me what they all were.  That would take the fun out of it.

The first had smooth gray bark on the trunk, but the twigs were more rust-colored.  The buds were opposite and were sort of a yellow or tan color, maybe with a reddish/brownish tint.  The branches split and pointed upward.

My observation of the second tree was cut short because when two people and a dog came by, I moved on. However, I noticed several of this kind of tree along the path, including one next to the above tree.  This tree was dark gray with lenticels.  The book I'm using,  A Guide to Nature in Winter indicates that if it has lenticels and catkins it's birch, if no catkins, it's cherry. I find the trees I see in reality often aren't in the books, but this tree had no catkins, and when I look at cherry twigs on the internet, it seems plausible that this could be cherry.