It can't really be called "the last great train robbery," because it was a failure as a robbery.
But the DeAutremont brothers (Ray, Roy and Hugh) made history when they stopped a Southern Pacific passenger train in the Siskiyou Mountains and killed four crews members back in 1923.
Railroad historian Scott Mangold uses previously unavailable materials in his retelling of the murders and the long manhunt that followed in his book Tragedy at Southern Oregon Tunnel 13.