Walnut is the same way. Very stringy wood. Burns well, though.Unlike elm which is all kinds of twisted fibers under the bark. NASTY to split.
Our black walnut trees grow to about 10-14" in diameter, then die. Very few get any real size to them, so it's not like we have a fortune in timber out there.
I just looked up what size they need to be to sell, and 22-26" diameter, minimum, and 28" would be even better, at 4.5 feet above ground.
Gonna go out with a tape measure sometime and see if we have ANY that big.