August 29, 1911: a man walked out of the hills near Lassen Peak and introduced himself as the last survivor of the Native American Yahi people. Contemporaries branded him “the last wild Indian,” but we will never know his true name.
The Yahi, a sub-group of the Yana, were mostly wiped out as part of the 19th century California Genocide. Essentially, the government of California endorsed the killing of the indigenous population to make way for (amongst other things) settlers of the California Gold Rush. The Three Knolls (1865), Campo Seco (1868) and Kingsley Cave (1871) Massacres reduced the number of Yahi down to perhaps 15.
By 1908, only a single Yahi was left. In 1911, he walked out of Lassen Peak and into the Western world. By Yahi tradition, you could not share your name unless you were formally introduced. However, being the only Yahi left, he had no-one to introduce himself, and so came to be known as Ishi (meaning just “man” in Yana).
Ishi lived for five more years, working and being studied at UC Berkeley. He contributed much to our understanding of stone tool making and language, and has been the subject of multiple books and films. (Side note: one of his biographers, Theodora Kroeber, was the mother of the acclaimed science fiction author Ursula K. Le Guin.) But he never told anyone his name.
[Thanks to David S for suggesting this topic.]