Robert E. Peary finally reached the North Pole for the first time on April 6, 1909. On May 9, 1926, Adm. Richard E. Byrd and Floyd Bennett became the first men to fly to the pole by airplane. Three days later, Lincoln Ellsworth, Umberto Nobile, and Roald Amundsen crossed the pole for the first time in a dirigible. In 1958 two U.S. submarines crossed the North Pole under the Arctic Ocean. Many nations are interested in the Arctic's resources, and the United States and the USSR each maintain a strong presence in the region. U.S. concern for the preservation of the Arctic environment led to the passage of the controversial Alaska Lands Bill in 1980.