The story that could be classified as folk tale is a) "The Orphan Boy and the Elk Dog" A Blackfoot Legend.
Folktales, by definition, are those stories and legends that originated from the lives and imagination of the people and their folklore, and they were oral literature transmitted from one generation to the next by a storyteller. Folktales were used to transmit the knowledge of the community and their legends. They do not have an individual author though they might be compiled by an editor.
In the case mentioned, "The Orphan Boy and the Elk Dog" is a 19th century folktale that explains how horses came to the Blackfoot Native American Tribe.
