Who is Arnulfo Quimare from Born to Run: A Hidden Tribe, Superathletes, and the Greatest Race the World Has Never Seen and what is their importance?

Taramuhara runner, Arnulfo Quimare, was the greatest living runner from his region. The author set out to find Arnulfo at the start of the novel. Arnulfo went onto run in the race at the end of the book.