Thursday, February 14, 2008

The Ancient Rivers


This ancient river of gold is by far the largest of the Tertiary rivers of the Sierra Nevada of California. It will be seen on Big Ten’s California Gold Map 5 that the Tertiary Yubu runs through or into the counties of Plumas, Sierra, Yuba, Nevada, Placer and El Dorado.

Ancient Yuba has numerous branches wandering throughout the area between Marysville and Lake Tahoe. The general drainage is from east to west; but in some of the branches the flow was from south to north and in other branches it was from north to south.

The Ancient Yuba River has been a rich source of gold. The famous gold towns of Grass Valley and Nevada City are along the course of the Ancient Yuba, as are the numerous gold deposit sites south of Downieville in Tahoe National Forest.

The deepest trough-shaped depressions in the drainage basin of the Tertiary Yuba River are usually filled to a depth of 50 to 200 feet by coarse gravels which ordinarily have been cemented so that they cannot be washed without crushing. Bench gravels

cover the deep gravels and in some places the bench gravels spread out to a width of one to two miles. The bench gravels contain much quartz. The pebbles are smaller than the deep gravels and always, except close to the headwaters, well rounded and polished. Fossil leaves have been found in the bench gravels.

The courses of the present-day Yuba River, including it’s North Fork, Middle Fork, South Fork and the smaller tributaries that feed them are also shown on Gold Map 5.


The Tertiary American River follows a more or less east to west course from south of Lake Tahoe to the town of Roseville northeast of Sacramento and Carmichael. It crosses California State Highway 49 a couple of miles south of gold-rich Placerville.


The Ancient Intervolcanic American River has many gold deposit sites along it’s course. It starts in Tahoe National Forest near the North fork of the present-day American river, then winds it’s way southwesterly to Auburn, Placer County. Many gold sites are near Auburn. One branch of the Ancient Intervolcanic American River circles around Volcanoville, which is noted for it’s gold.

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