who
have written on the subject of forests are correct, these floods will
increase in magnitude with the destruction of timber in the Sierra.
THE BELT OF THE SIERRA NEVADA.
Topographical Structure.—The
Sierra Nevada is a well-defined range of mountains situated on the edge
of a high plateau, its eastern base being about four thousand feet
high, while its western side slopes nearly to the sea-level. Its
eastern flank is comparatively short and steep; its western, long and
with a gradual descent, averaging in the central part of the State
about one hundred feet per mile. This west side is broken by steep
canons in which the present rivers flow, running at about right angles
with the axis of the ridge, so that an elevation of three thousand to
four thousand feet above the sea-level the divide between any two
streams is from several hundred to two thousand feet, or more, above
the bottoms of the canons on either side.
In
the northern part of the State the range is outlined indistinctly,
consisting of broken ridges with several prominent peaks. The general
elevation may be assumed to be seven thousand or eight thousand feet.
Mount Shasta, the highest point of this section, rises to a height of
fourteen thousand four hundred and forty feet, dominating over all the
others. South of this, from Lassen's Peak (lat. 400 40' N.) to near Tejon Pass (lat. 350
N.), the Sierra Nevada forms one clearly defined crest, gradually
increasing in height toward the south. Along the headwaters of the
Feather River, in Plumas and Sierra counties, the elevation of the
prominent peaks is about nine thousand feet, and of the passes from
five thousand to six thousand feet. Lassen's Peak rises ten thousand
five hundred feet above the sea-level. The western slope here has a
total width of some eighty-five miles.
Around the head-waters of the American River, in Nevada, Placer, and El Dorado counties, the main crest is
