eliminate lots of guesses
Nathan,
If you take a closer look you can probably tell easily if it is or is not white oak, cherry, walnut, or any of the many likely guesses. If you are not experience with the different species, maybe cut a smaller piece and take it to someone with experience. Walnut, for example has a very distinctive smell as do red oak and cherry. The color of freshly cut surfaces of these three are also distinctive, something not always possible to show in a photo of a log. You can compare the bark to photos but that looks like a large log and trees that are both quite young or quite large are often harder to distinguish from the bark.
Examining a small section of the end grain is the best way to tell what it is NOT, for example, you can instantly tell by the pores and rings and rays if it is not oak. It is easy to check - all you need is a little piece about 1/2" square , a single-edged razor blade, and a small magnifying glass (or good eyes, in the case of oak). You can usually cut off a piece with a pruning saw and an hatchet or chisel. It doesn't need to be cut from the biggest cross section but it is better if it is heartwood instead of sapwood.
Section 7 in this article has good instructions: http://www.wood-database.com/wood-ar...ication-guide/
JKJ