Like others have said, Red Elm, Ulmus Rubra, it's interlocking grain makes it difficult to split. Bring extra wedges and a buddy.
I've made one bow with it, a much smaller diameter, actually a limb from storm cleanup. I used a flat bow design, long, wide and performance was good (to me at least), and long before I learned about heat treating.
Took a bit of set as recall, probably being impatient with drying after splitting.