our forests. Several of the States, including New York and
Pennsylvania, have purchased large areas of timberlands for State
forests. These will be developed as future sources of lumber
supply.




CHAPTER III

FORESTS AND FLOODS


Forests are necessary at the headwaters of streams. The trees
break the force of the rain drops, and the forest floor, acting
as a large sponge, absorbs rainfall and prevents run-off and
floods. Unless there are forests at the sources of streams and
rivers, floods occur. The spring uprisings of the Mississippi,
Ohio and Missouri Rivers are due largely to the lack of forests
at their headwaters. In the regions drained by these streams the
run-off water is not absorbed as it should be. It flows unimpeded
from the higher levels to the river valleys. It floods the river
courses with so much water that they burst their banks and pour
pell-mell over the surrounding country. Many floods which occur
in the United States occur because we have cut down large areas
of trees which formerly protected the sources of streams and
rivers.

A grave danger that threatens western farming is that some time
in the future the greater part of the vegetation and forest cover