The granite of Mt. Rushmore gives in to the forces of erosion at a rate of one inch every 10,000 years. In human terms, that amounts to no erosion at all; 10,000 years ago, our species was just discovering agriculture (http://alamanach.com/untitled/). Rock that hard could not have been easy to carve. Still, erode it does; Mt. Rushmore, like everything, is forever in a process of becoming something else.
After the United States bought the Louisiana Territory from France, Thomas Jefferson sent explorers to find their way across. The main purpose of the Lewis and Clark expedition was to find a navigable water route across the continent that would facilitate commerce.
There is no navigable water route across the continent. A meandering line runs the length of North America, and no water crosses it. We call this line the Continental Divide. Continue reading
…Corrigan insisted that in the dark, he couldn’t tell that he’d been following the wrong end of the compass needle. By the time the sun had come up, it was too late for him to turn back…