FORMER THEORIES IN REGARD TO THE GRAVEL DEPOSITS. 67 
newspapers in regard to this question, — as well as about the origin of the 
gold in the different formations. The idea that these immense gravel accu- 
mulations were in some way the result of ancient river action began to gain 
ground, although vehemently opposed by many. It is very easy at the pres- 
ent time to understand the cause of the great diversity of opinion among 
the miners. The idea of an ancient river formation was at first always 
connected with the existence of one river, and not of many. This arose 
from the fact that the high gravels were exposed, during the earlier years of 
hydraulic mining, chiefly along a certain belt of the Sierra, at various points 
of nearly equal height above the sea, exhibiting at these points very simi- 
lar appearances, so that they seemed to be portions of one consecutive 
formation crossing the present system of rivers nearly at right-angles. 
Thus Dr. J. B. Trask, who conducted a geological reconnaissance of 
the State, under authority of the Legislature, during the years 1852 — 55, 
in his second Report of work done in 1853, speaks of an ancient stream 
flowing with a breadth of about four miles, at an elevation of 4,000 feet 
above the sea, from Butte to El Dorado County.* This stream he calls 
the “ Eastern Blue Range,” and he describes its peculiarities with con- 
siderable detail, tracing it from the South Fork of Feather River as 
far as Georgetown. According to Dr. Trask, the boulders found in this 
range of gravel are almost exclusively quartz, surrounded by an earthy 
material of a deep blue color, giving a very marked character to the 
* “Tt 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 are similar in all respects to that in the older or more western sections, with perhaps one ex- 
ception, 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. From the 
examinations that were made upon this range, there are abundant evidences that an ancient stream flowed 
through this section of the country, and in a direction parallel with its then existing mountain ridges, and 
the extensive mining operations conducted in the southeast part of Sierra County on this range, has been 
the means of demonstrating this fact, which had heretofore been strongly suspected only. The outliers of 
its banks are very definitely marked throughout the entire length of the formation under consideration, 
and its former bed filled in many places with a volcanic sand and ashes, which probably accompanied its 
displacement.” — J. B. Trask, M. D., in Report on the Geology of the Coast Mountains and Part of the 
Sierra Nevada, Doc. No. 9, Session 1854. pp. 61, 62. 
