In 1913 a party set out to map Crocker Land, "a huge island supposedly sighted by the explorer Robert Peary from the top of Cape Colgate in 1906." Peary had named it after San Francisco banker George Crocker, one of his backers. According to Wikipedia, "it is now known that Peary's claim was fraudulent, as he wrote in his diary at the time that no land was visible."
Donald MacMillan led the expedition anyway, calling Crocker Land "the world's last geographical problem." After a 1,200-mile journey across treacherous sea ice, on April 21, 1914, the men saw what looked like "Hills, valleys, snow-capped peaks extending through at least one hundred and twenty degrees of the horizon." An Inuk hunter named Piugaattoq, with 20 years of experience in the area, explained that it was just an illusion. He called it poo-jok, which means "mist."
MacMillan pressed on for five more days before admitting the land was a mirage, "probably a rare form of mirage called a Fata Morgana." On the way back, after the party split up, Navy ensign Fitzhugh Green shot Piugaattoq in the back and killed him during an argument over which way to travel. Green was never prosecuted.
