PLACER MINING.
The writer enters into a long treatise on this branch of mining, and represents its progress as being very extensive during the last two years.
It is now ascertained to a certainty that the placer ranges extend to the east, within ten or fifteen miles of the “summit ridge,� so called, of the Sierra Nevada; and the condition in which it is found at these points is similar in all respects to that in the older or more western sections, with, perhaps, one exception, and that the relative age of both. There are evidences which clearly indicate a deposit of gold older than the diluvial drift of the lower or western diggings, (which latter is often confounded with the drift deposits of the tertiary periods in this country,) the character of which differs in almost every respect from any other deposit yet observed in this country, except in this particular range.
Its direction has been traced for about seventy miles, and is found to extend through the counties of Butte, the eastern part of Yuba, Sierra Nevada, Placer and El Dorado; it appears to have an average breadth of about four miles, with an elevation of four thousand feet above the sea for the greatest part of its length.
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