IN THE SIERRA FOOT-HILLS Murphy's camp is a curious old mining-town in Calaveras County, at an elevation of 2400 feet above the sea, situated like a nest in the center of a rough, gravelly region, rich in gold.

Granites, slates, lavas, limestone, iron ores, quartz veins, auriferous gravels, remnants of dead fire-rivers and dead water-rivers are developed here side by side within a radius of a few miles, and placed invitingly open before the student like a book, while the people and the region beyond the camp furnish mines of study of never-failing interest and variety.
When I discovered this curious place, I was tracing the channels of the ancient pre-glacial rivers, instructive sections of which have been laid bare here and in the adjacent regions by the miners.

Rivers, according to the poets, "go on forever"; but those of the Sierra are young as yet and have scarcely learned the way down to the sea; while at least one generation of them have died and vanished together with most of the basins they drained.

All that remains of them to tell their history is a series of interrupted fragments of channels, mostly choked with gravel, and buried beneath broad, thick sheets of lava.

These are known as the "Dead Rivers of California," and the gravel deposited in them is comprehensively called the "Blue Lead." In some places the channels of the present rivers trend in the same direction, or nearly so, as those of the ancient rivers; but, in general, there is little correspondence between them, the entire drainage having been changed, or, rather, made new.