by Gray Merriam
The Salmon Watershed
Headwaters means the places where a river starts. First it is a trickle that soon further downhill will be joined by another trickle to form a flow that is hard to jump across. As other sources add their flows the stream becomes a substantial creek. Creeks flow together and a river is formed.
The beginning trickle of one watershed is likely to be very close to a beginning trickle that flows the other way into a neigbouring watershed. The land that separates them is called ‘the height of land’ and it is mapped as the watershed boundary.