Father in law is trying to find out if this might be good fire wood. He handed me a small piece of bark, piece from the middle, and a small branch. The bark is rough & brownish, the inside of the tree is a yellowish-orangish type of color (never saw anything like it - distinct), and the branch has thorns with ovate leaves. He says they are very tall & big. Is that enough specifics that somebody might know what it is? I looked through all of my literature but couldn't match it. Thanks for any help.