John Ermine of the Yellowstone.

As a baby, John Ermine is stolen from a wagon train by the Crow Indians and is adopted by Chief Fire Bear. John grows to manhood, ignorant that he is a white man until his parentage is disclosed to him by Crooked Bear, a white hermit who is on friendly terms with the Crows. Crooked Bear teaches John the language and customs of the white man's civilization, impressing upon him that it is his sacred responsibility to keep peace between the white men and the Indians.