This tree grows along a narrow but frequently used path along a creek in a city park. It has large spines on its trunk, most of which have been cut or flattened, probably to prevent people being impaled. The trunk is green between spines. Most of the leaves have fallen, but the few dead ones still attached didn’t look like compound leaves, which would rule out the two spiny trees I’m familiar with here, Hercules' Club and Prickly Ash.