We know that the processes of erosion and weathering will continue, that
alluvial fans and talus cones will grow larger, and gorges will be
eroded deeper, and as a result the mountains will be cut down to lower
elevations. But, as we have seen, this event will require much time. If
the present climate continues for a few more years our remaining
glaciers will disappear, but there is nothing in geologic history which
says they won't return again, possibly even to the size of their heyday
in the Pleistocene. And if history repeats itself, and all past geologic
history has been a repetition, then the mountains will eventually be
worn down to an uneventful plain and the sea will invade the land again.
But certain breeds of man are the only despoilers of mountains that we
need fear, so if the good citizens of our land keep the human invader
and his dams and earth-moving equipment out of our national parks these
grand mountains will endure for many thousands, yes, even millions of
years.