Every storm that falls upon them wastes them, carrying away their decaying, disintegrating material into new formations, until they are no longer recognizable without tracing their transitional forms down the Range from those still in process of formation in some places through those that are more and more ancient and more obscured by vegetation and all kinds of post-glacial weathering.

It appears, therefore, that the Sierra forests indicate the extent and positions of ancient moraines as well as they do belts of climate.
One will have no difficulty in knowing the Nut Pine (Pinus Sabiniana), for it is the first conifer met in ascending the Range from the west, springing up here and there among Douglas oaks and thickets of ceanothus and manzanita; its extreme upper limit being about 4000 feet above the sea, its lower about from 500 to 800 feet.

It is remarkable for its loose, airy, wide-branching habit and thin gray foliage.

Full-grown specimens are from forty to fifty feet in height and from two to three feet in diameter.

The trunk usually divides into three or four main branches about fifteen or twenty feet from the ground that, after bearing away from one another, shoot straight up and form separate summits.