This is one of the largest species of scorpions in the U.S., with mature adults growing to about 5 inches long from tip of tail to head. The legs, claws, tail appendage and underside are all a light yellow colour while the top of the cephalothorax is a charcoal black. The tips of the claws are a reddish brown. The body is covered with a light layer of fine, short hairs used to detect movement in its environment.