The myth or legend of Hannibal’s Lover’s Leap was written by a man named Aurthur O. Garrison, who claimed that he obtained the details from “ancient inscriptions and a birch bark manuscript.”
No one seems to know who Garrison was. The clipping of his story has vanished and none know what newspaper or book it was taken from or when it was published.
These myths aren't as harmless as the author thinks. Rather, they're stereotypical and as harmful as other Native stereotypes. They convey the idea that Indians were weak, impulsive creatures of passion. That everything about them was romantic, sad, and tragic. That they were destined to vanish because of their own failures--not because of America's genocidal policies against them.
And most of all, that they're primitive people of the past. You'll never hear that someone leapt after graduating from a university, translating the Bible into a Native language, or winning a court case. Like Indian mascots, hipster headdresses, and Thanksgiving pageants, these stories are about keeping Indians in the past. If we can make everyone forget our crimes against them, we don't have to redress their ongoing grievances.
For more on the subject, see Debating Frog Woman Rock and Legend of Lovers Leap.