s on
their courses to the ocean.

I cannot, however, present all the evidence here bearing upon these
interesting questions, much less discuss it in all its relations. I
will, therefore, close this letter with a few of the more important
generalizations that have grown up out of the facts that I have
observed. First, at the beginning of the glacial period the region now
known as the Great Basin was an elevated tableland, not furrowed as
at present with mountains and valleys, but comparatively bald and
featureless.

Second, this tableland, bounded on the east and west by lofty mountain
ranges, but comparatively open on the north and south, was loaded with
ice, which was discharged to the ocean northward and southward, and
in its flow brought most, if not all, the present interior ranges and
valleys into relief by erosion.

Third, as the glacial winter drew near its close the ice vanished from
the lower portions of the basin, which then became lakes, into which
separate glaciers descended from the mountains. Then these mountain
glaciers vanished in turn, after sculpturing the ranges into their
present condition.

Fourth, the few immense lakes extending over the lowlands, in the midst
of which many of the interior ranges stood as islands, became shallow
as the ice vanished from the mountains, and separated into many distinct
lakes, whose waters no longer reached the ocean. Most of these have
disappeared by the filling of their basins with detritus from the
mountains, and now form sage plains and "alkali flats."

The transition from one to the other of these various conditions was
gradual and orderly: first, a nearly simple tableland; then a grand mer
de glace shedding its crawling silver currents to the sea, and becoming
gradually more wrinkled as unequal erosion roughened its bed, and
brought the highest peaks and ridges above the surface; then a land of
lakes, an almost continuous sheet of water stretching from the Sierra
to the Wahsatch, adorned with innumerable island mountains; then a slow
desiccation and decay to present conditions of sage and sand.

XVI. Nevada's Dead Towns [21]

Nevada is one of the very youngest and wildest of the States;
nevertheless it is already strewn with ruins that seem as gray and
silent and time-worn as if the civilization to which they belonged had
perished centuries ago. Yet, strange to say, all these ruins are results
of mining efforts made within the last few years. Wa