I prefer oak on beef, hickory or pecan on pork.
Jeff, be warned. Most folks selling you split wood have no clue as to what is/isnt
oak, hickory, or anything else. I cannot tell you how many cords (many have no idea
what a cord is, but they'll sell it to you) of hickory I've purchased had 0 hickory in
it and was chock full of poplar, sweet gum and various oak.
No, it's nearly impossible to tell apart, even if the bark is there. Too many trees bark resembles hickory, but if you see the tree before cut-down they're very easy to identify (especially if they have leaves).
Hance - Lake Dogs Cooking Team - MiM/MBN/GBA CBJ and comp cook
Lake Sinclair, GA (strategically about an hour from everywhere)