"Thousands of pack horses lie dead along the way, sometimes in bunches under the cliffs, with pack saddles and packs where they've fallen from the rock above, sometimes in tangled masses, filling the mud holes and furnishing the only footing for our poor pack animals on the march, often, I regret to say, exhausted, but still alive, a fact we were unaware of, until after the miserable wretches turned beneath the hooves of our cavalcade.