I'm reading lots about a white bass run. Is there anywhere in the DFW are where one can wade and catch these guys on flies?

yes.

I do a lot of wade fishing for Sandies on the fly but you have to have a boat to get to the places to wade. They are surrounded by farmland and the landowners are funny about trespassing.

Texas creeks can be tough to wade, downed timber and deep holes interspersed with big rocks make it work. However the Nolan river near Blum can be a blast when water conditions are right for sand bass. Need current and have to have some rain for that. The Brazos can offer some good fishing also but wading it can require a canoe just to get to good wading water.

Absolutely. Google maps is your friend.