I have a maple tree on my front lawn. At about 11 feet where the two leaders...
I have a maple tree on my front lawn. At about 11 feet where the two leaders separate, the bark is falling off one side of the tree for a length of about 4 feet in the upward direction. I do not see any carpenter ants, but carpenter ants have killed 3 trees on my front lawn over the last 25 years.
Carpenter ants move into damaged wood, but they don't actually kill the trees. They simply nest in the wood. (They don't eat wood, like termites do.)
We can't say what is affecting your trees. We'd recommend that you contact tree service companies and have them send out a certified arborist to look at the tree. The arborist should be certified by the International Society of Arboriculture and you can locate the companies with them in your vicinity by using this website: www.treesaregood.org.
Typically, there is no charge for a visit, only any work you hire them to do. And you can get more than one opinion by having several companies look at the tree before you decide on any work.