"David Ingram, an English adventurer, was put ashore with 113 other men between Mexico and Florida in 1568, and he wandered for years in the American interior before making his way to the east coast of the American colonies. In his report to the state secretary of Queen Elizabeth, he described precisely and drew accurate pictures of elephants as well as bison and other animals he and his companions had observed during the journey. Ingram could not have known that some centuries later, elephant bones (mastodons and mammoth) would be discovered all over the continent. This account is not taken seriously, but it is a curious fact that 200 years later President Jefferson was informed by a delegation of Indian chiefs that hunting in the interior lands included animals described as elephants. It is a matter of record that President Jefferson asked Lewis and Clark to be on the alert for elephant herds during their exploration of the West" (Internet).
I wonder if the mastodon was what they were talking about? The mastodon was a forest creature, and (in its known period of existence) was found mostly east of the Mississippi; the mammoth was found mostly west. Anyway, thanks, it’s another uncertainty which has an outside chance of someday being verified by a find of recent remains.