In July 1908, when Whitney was 34 years old, he and two "sportsman" friends found berths on the "Roosevelt" and the "Erik", the ships carrying Peary's expedition north for his final attempt to reach the Pole. Whitney and his friends hoped to hunt musk ox, polar bears, and other arctic game and then return on the ship. However, upon reaching Etah, Greenland, they learned that musk ox could only be hunted in the late winter. Whitney decided to overwinter in a small shack made from packing materials on the shore. His friends returned to New York aboard the "Erik". The "Roosevelt" continued on to Peary's base camp at Cape Sheridan, Ellesmere Island.