Myths and Legends of our Own Land, by Charles M. Skinner, [1896], at sacred-texts.com
In the country about Tishomingo, Indian Territory, troubles are foretold by a battle of unseen men in the air. Whenever the sound of conflict is heard it is an indication that many dead will lie in the fields, for it heralds battle, starvation, or pestilence. The powerful nation that lived here once was completely annihilated by an opposing tribe, and in the valley in the western part of the Territory there are mounds where hundreds of men lie buried. Spirits occupy the valley, and to the eyes of the red men they are still seen, at times, continuing the fight.
In May, 1892, the last demonstration was made in the hearing of John Willis, a United States marshal, who was hunting horse-thieves. He was belated one night and entered the vale of mounds, for he had no scruples against sleeping there. He had not, in fact, ever heard that the region was haunted. The snorting of his horse in the middle of the night awoke him and he sprang to his feet, thinking that savages, outlaws, or, at least, coyotes had disturbed the animal. Although there was a good moon, he could see nothing moving on the plain. Yet the sounds that filled the air were like the noise of an army, only a trifle subdued, as if they were borne on the passing of a wind. The rush of hoofs and of feet, the striking of blows, the fall of bodies could be heard, and for nearly an hour these fell rumors went across the earth. At last the horse became so frantic that Willis saddled him and rode away, and as he reached the edge of the valley the sounds were heard going into the distance. Not until he reached a settlement did he learn of the spell that rested on the place.