This is the first year that I have seen fruit on the tree, and there is only the one. Black walnut is the closest I can get from searching the web. Can anyone confirm? Here is a full view of the tree. It's about 6 feet tall. And this is the fruit.
Tamster02- Oklahoma, Zone "7"
Why, yes. I do believe you have yourself some good eats there. From that photo it appears to be a Juglans nigra (Black Walnut) or Juglans microrapa (Texas Walnut). Amazingly enough the Texas variety is the more diminutive of the two ;)
Mrmunk- Georgia, Zone "7b"