An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 m. Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth âs surface. They are among the flattest, smoothest and least explored regions on Earth.
Jim Beckwourth. On this day in 1844, Jim Beckwourth discovered a path through the Sierra Nevada Mountains that now bear his name. Beckwourth Pass on U.S. Alt 40 between Reno, Nevada and Sacramento, California made overland travel to the gold fields of California. Tweet.
Introduction. The southeastern face of Mount Rushmore in South Dakotaâs Black Hills National Forest is the site of four gigantic carved sculptures depicting the faces of U.S. Presidents George Washington, Thomas Jefferson, Abraham Lincoln and Theodore Roosevelt.orglum suggested that the subjects of the South Dakota work be George Washington and Abraham Lincoln, as that would attract more national interest. He would later add Thomas Jefferson and Theodore Roosevelt to the list, in recognition of their contributions to the birth of democracy and the growth of the United States.