This story appears in the November 2013 issue of National Geographic magazine ... and William Clark on their epic journey across North America. The other one is just beginning.

8 min read This story appears in the September 2013 issue of National Geographic magazine. The maps here show ... Basin in the north and the Paraguay River Basin in the south would become Atlantic ...

North America is the third largest continent in the world. It is located in the Northern Hemisphere. The north of the continent is within the Arctic Circle and the Tropic of Cancer passes through ...

The Pacific Ocean is to the west of South America and the Atlantic Ocean is to the north and east. South America contains twelve countries in total. These include Argentina, Bolivia, Brazil and Chile.