By the late 1850s on into the 1860s, as the westward moving tide of emigrants increased, so did hostilities with the Indian tribes whose lands they passed through. In this painting, the viewer can feel the intensity and energy of these galloping Sioux and Cheyenne fighters as they harass a wagon train crossing the Medicine Bow Mountains. This painting projects a powerful sense of action, from the cadence of horses' legs, to the directional movement established by arms brandishing guns, bows, lances, and a warrior society flag!