“Reports of depredations, whether accurate or not, combined with the guidebook advice, predisposed overlanders toward treating all Indians with suspicion and distrust. . . . Thus primed, overlanders were responsible for many incidents which, while often humorous, were sometimes deadly. While these usually occurred at the inception of the journey, all along the trail forty-niners and subsequent overlanders shot at one another, at their own oxen, mules, horses, and sheep, at saddles and blankets, at elk, and even at pelicans. All had been mistaken for marauding Indians.”