My 2 sugar maples have gall.
The trees are over 30 ft tall and have been effected for several years. The first tree it started on has lagged in growth and leaf production. Everything I read about the condition says it will not harm the trees, yet this year the first tree has no leaf production while the 2nd one has leafed out. My question is, Is my tree dead?
Galls do not seriously affect the health of the trees. http://extension.umd.edu/hgic/shade-tree-galls
Your trees may be declining for other reasons such as drought, poor soils, poor drainage, planting too deeply, girdling roots, etc. Look at our publication on these types of problems. http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG86%20Common%20Abio...
When subject to this they can be susceptible to insect and disease issues.
Scratch the branches with your fingernail and look for green tissue. If you see it, then the branches may still be viable. Otherwise the tree sounds like it may be dead. See our publication on When to Remove a Tree. http://extension.umd.edu/learn/how-do-you-decide-when-remove-tree
You also have the option of contacting a certified arborist regarding the health of the tree and the best way to proceed. http://www.treesaregood.org/