A horde of jara, the Pig Tramplers, once made their way up this canyon. They razed the outlying settlements of the Neeth-Theen, putting all creatures in their path to the sword. On nearing the realm of Flux, the canyon and Molfath abruptly changed shape.
The Jara Horde, some estimate they numbered 20,000, became enclosed in a canyon with few rocky paths leading out. The Neeth-Theen organized their forces and blocked all routes of escape. Over the ensuing weeks, the Pig Tramplers was slaughtered without remorse. Beasts of chaos rose from the bubbling pools of Bone Hoof Canyon attacking without fear. Missile fire was without pause, and like herd beasts, jara stampeded, frequently trampling their wounded brethren. Flying creatures harried the jara, dropping missiles, or raking the flesh of the beasts. In the end, Ushgergoon, a mighty slaad leader, waded into the ranks of the Jara Horde, swinging his greatsword called Oblivion, dropping three or four jara with each swing.
The Bone Hoof Canyon occasionally opens up. This phenomenon is produced by the strong presence of the Chaos Malestrom, which affects all of Flux. The jara avoid the haunted canyon. Some of those that perished from the sword Oblivion became restless souls. These undead creatures spit curses on those entering the valley and attack with disruption and warping powers. The restless souls also keen with their last dying wails. The effect of this is just like a groaning spirit.