South America the Darién watershed along the Colombia–Panama border, although some may consider the border instead to be the Panama Canal. Geopolitically and geographically all of Panama – including the segment east of the Panama Canal in the isthmus – is typically included in North America alone and among the countries of Central America. Almost all of mainland South America sits on the South American Plate. South America is home to the world's highest uninterrupted waterfall, Angel Falls in Venezuela; the highest single drop waterfall Kaieteur Falls in Guyana; the largest river (by volume), the Amazon River; the longest mountain range, the
American Falls Dam the present American Falls Dam formed a reservoir in which more than of sediments (clay, silt, and sand) were deposited. This series of basalt flows and original sediments were covered by the new lake bed sediments and are named the Snake River Group and the American Falls Lake Beds. These events occurred up until the late Pleistocene, less than one million years ago. The Snake River has continued to erode its channel in the basalt and modify the lake bed sediments until the present time. The dam at American Falls is on the Snake River Plain at an elevation of