Aborigines

Strength was in numbers, and if you kept with the bulk of the troops you would stand a chance if forced into a last stand. The horses were exhausted, terrified, and wild-eyed. The red stone walls on either side began to spread further apart, allowing more breathing room for the men. It was good; you didn't need to get bottlenecked. The Apaches obviously corralled you into the canyon on purpose. Perhaps they had wanted you to go left.
Behind you were a number of warriors, no longer firing their weapons at you, just chasing you deeper in. There were significantly less than there were before, as most had branched left to overpower the men who had gone that way. Your adrenaline-pumped mind didn't register the grim significance of that fact until it was too late.
Up ahead came the sound of passionate cursing. At first you think the Apaches had cut you off up ahead, but you quickly realize your error. In front of you, men were vanishing in thin air. Before the confusion could make way into understanding, you see why: the Apaches had driven you into a ravine! Soldiers were flying off the cliff edge in droves, their frightened horses unable to slow down before they began plummeting to their deaths. You yank at the reins as hard as you can, but it is in vain. The sensation of falling took hold in your stomach for the exact two and a half seconds it took to reach the bottom.
End Of Story