All rivers start off in high valleys or mountains. This is called the mouth of the river. It is also called The Young river or upper course of the river. This is where there are large sharp rocks bellow the waters surface and the water is flowing the fastest.
This is the middle course or middle age section of the river.As you can see the river has widened ot and has a slower flowing current. The rocks on the bottom of the river and smooth and have no sharp edges due to river erosion
Take Care, Deep Water!
This is the old river or the lower course of the river. Here the river flows even slower than beforend as almost doubled in width. Here the stones on the bottom of the river have become nothing but tiny smooth pebbles.