Usually at the top of mountains, they start off as streams. Then the streams join together and get bigger, wider, and eventually they turn into rivers.
At their source
At the top of a mountain or hill.
Chicken
Most of the rocks are located by beaches and rivers. It is stated that beaches and rivers are very good places to start a persons rock education from scratch.
Small streams flow into rivers and the rivers flow to bigger rivers.
The Indus and the Ganges Rivers
itaska
The Amazon
The watershed.
oceans
What is unusual about most of the rivers in Mexico? *
NO. There are many rivers that begin in countries that have no mountains. Rivers ofter start from a spring that feeds a creek that then joins with other creeks or streams to become a river.
Most of Australia's rivers are in the eastern third of the continent.
Alaska, by far, has the most lakes. Don't know about rivers, but it wouldn't shock me if they have the most rivers, too.
There are waterfalls in most rivers.