Question
I recently took over maintenance of an RV park in the Coastal Bend area of Texas.  There are hundreds of huge live oaks that have been neglected. Lots of dead limbs on them. I have identified white flies and gall wasp. Also lots of grape vines, cow itch vines and yaupons.  What do I need to do to bring them back to health?

Answer
I would recommend cutting the grape vines, cow itch vines and the yaupons. Then thinning the dead limbs off the live oaks. Fertilize them with a all around fertilizer 13-13-13.
I feel it maybe more complicated than your short question so I would also recommend that you contact the Texas Forest Service and ask one of their Forester to come out and check your trees and advice you what needs to be done. There is a disease called oak wilt in that part of the county and you need to make sure the oaks are not effected. Check in the local phone book for a phone number for the Texas forest Service ( state agency).
Here is the contact for the oak wilt folks if you want to contact them they can also give you the local contact for on the ground assistance.
http://txforestservice.tamu.edu/contacts/default.asp?strLocation=LUFKIFRSTPEST