Road from Canyon to Lake Yellowstone also has thermal areas. Ethnographic information relates this thermal area to the Kiowa origin myths. The Dragon's Mouth may be their 'center of creation'. Crow tribal narratives also feature this area.
(Note: Kiowa ethnography, see Nabokov & Loendorf, "Restoring a presence: American Indians and Yellowstone National Park" 2004, p. 67ff. Crow ethnography on this area, see p. 81).