Lonesome Dove, Volume 2: Comanche Moon by Larry McMurtry

FAMOUS SHOES was traveling by night, covering as much ground as he could, when he heard the singing to the south. At first, when he was far from the singer, he thought the faint sound he heard might be a wolf, but as he came closer he realized it was a Comanche, though only one Comanche. All that was very curious. Why would a single Comanche be singing by himself at night, on the llano?

He himself had been to the Cimarron River, where a few old people of his tribe still held out. He had been showing some of the flints he had found while tracking Captain McCrae to some of the oldest of the Kickapoos. Over the years since his discovery he had shown the flints to most of the oldest members of his tribe, and they had been impressed. He had been back several times to the place where he found the flints, and had located so many arrowheads and spearheads that he had to take a sack with him, to carry them. He had found a fine hiding place, too, on the Guadalupe River, a small cave well concealed by bushes, which is where he hid the flints that had been made by the Old People.