The Ancient American River, Ancient Yuba River, Ancient Calaveras River, Ancient Mokelumne River, Ancient Tuolumne River, Ancient Magalia Channel, Ancient Intervolcanic Cateract Channel, Ancient Intervolcanic American River and the Ancient Jura River (from the Jurassic Period), are plotted in detail on Big Tenís California Gold Map 5. The present-day rivers bearing the same names as their ancient rivers are also shown.
The Ancient Rivers of Gold in Northern California are from the Tertiary Period. The Tertiary rivers existed millions of years ago and many of them had large quantities of gold within their gravels. Because of that, they are known as the "Ancient Rivers of Gold." Each ancient river is discussed below.
Information on this page is based on the classic work of Waldemar Lindgren of the United States Geological Survey and by study of Big Tenís California Gold Map 5, which shows the relationship of the ancient rivers to landmarks, such as roads, creeks and towns in the region.
These now-dry Tertiary rivers are thought to be a prime source of the gold found in many of the rivers and streams of the Mother Lode region of northern California. The ancient rivers are discontinuous and sometimes follow tortuous routes. They have been altered by volcanic activity, erosion, and in some instances portions of the rivers have been covered by lava. Much of the region underwent extreme volcanic eruptions. Volcanic flows have been found up to 4,000 feet deep. Volcanic flows were up to 60 miles in length. Portions of an ancient river may be found at ground level or near the top of a mountain, or on the side of a mountain, or buried.
Early prospectors found portions of the ancient rivers and worked them for their rich gold content. Later, mining companies used hydraulic mining or drift mining techniques to recover the gold. In hydraulic mining, water under pressure is directed to, for example, the side of a ravine to dislodge the gravels and send the material to the sluices where the gold is recovered. The equipment that was used (called a "monitor" or "giant") was similar to a very large hose nozzle.
Geologic reports speak of gravel deposits up to 250 feet deep with gold deposits interspersed at various levels within the gravels. Some of the gravels of the ancient rivers of gold have been cemented together over time. Smaller materials between the larger gravels have bound the larger gravels together. Drift mining is used in those instances to follow the channel underneath the volcanic covering. In drift mining, tunnels are driven in bedrock underneath the channels and when the channels are reached, the richest stratum, resting immediately on the bedrock, is extracted by underground mining methods and then washed at the mouth of the tunnel.
Many miles of the ancient rivers are still un-worked and may be very rich in gold.
SOME OTHER MINERALS OF THE ANCIENT RIVERS OF GOLD
Platinum is widely distributed in the gravels of the Tertiary rivers of the Sierra Nevada. The platinum is always associated with the gold. Some of the counties where platinum has been proven to be present in the sands are: Butte, Calaveras, Nevada, Placer, Plumas, Sacramento and Yuba.
Garnet is widely distributed especially in the vicinity of granitic contacts. It is usually found in small rounded grains of red to purplish color. The largest quantity recorded was from the black sands at Rough and Ready, Nevada County at 446 pounds to the ton.
Zircon is universally present. In some local areas it has been found in considerable quantities, such as at Placerville and at the North Fork of the American River in Placer County. The greatest relative quantity was found in black sand from a channel at Nevada City. It yielded 928 pounds to the ton.
Small flakes of metallic copper are occasionally observed.
Pyrite is of common occurrence in the gravels.
Diamonds have been found to occur with the gold, mainly at Cherokee Flat in Butte County and in the gravels at Placerville, El Dorado County. The diamonds that have been found were generally of small size and yellowish color. As is the case of diamonds in North Carolina and South Carolina, the diamonds in the California Mother Lode region are mostly scattered. Diamonds come up through the rock through a "pipe" of relatively small diameter, such as the diamond pipes in South Africa. (The state of Arkansas has acquired a diamond property at Murfreesboro where the public is permitted to search for diamonds. The diamonds are of good size and high quality. The Arkansas property is Crater of Diamonds State Park.)
YUBA ANCIENT RIVER OF GOLD
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 Tenís 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 itís North Fork, Middle Fork, South Fork and the smaller tributaries that feed them are also shown on Gold Map 5.
AMERICAN ANCIENT RIVER OF GOLD
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.
ANCIENT INTERVOLCANIC AMERICAN RIVER
The Ancient Intervolcanic American River has many gold deposit sites along itís course. It starts in Tahoe National Forest near the North fork of the present-day American river, then winds itís 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 itís gold.
ANCIENT MAGALIA CHANNEL
Magalia Channel is just north of Paradise, Butte County and gold sites are on both sides of the channel. A 54 pound nugget was found at Magalia. The West Branch of Feather River runs near and crosses this ancient channel south of Last Chance Creek.
ANCIENT JURA RIVER
The Ancient Jura River is from the Jurassic Period, which makes it much older than the ancient rivers of the Tertiary Period. The course of this ancient river traces from Sierra County past Blairsden and Cromberg in Plumas County and Mount Ingalls. There are very few gold sites along the Jura River.
MOKELUMNE ANCIENT RIVER OF GOLD
Tertiary Mokelumne River starts in Eldorado National Forest and runs westward. It terminates about 8 miles west of California State Highway 49 not far from the town of Plymouth in Amador County. Two branches of the river originate near the North Fork of the Cosumnes River. Quite a few gold sites occur along the westernmost branch and along the main course of the ancient river near the towns of Volcano and Plymouth.
CALAVERAS ANCIENT RIVER OF GOLD
A considerable number of gold sites parallel the Tertiary Calaveras River. Tertiary Calaveras itself parallels the South Fork of the Stanislaus River just north of Columbia Historical State Park. The ancient river continues westward to California State Highway 49 and parallels the gold camps north to San Andreas. It terminates near Valley Springs in Calaveras County.
Rich gold deposits occur near the branches of ancient Calaveras. Hundreds of gold sites appear on Gold Map 5 along and between the two northern branches that originate near the towns of Sutter Creek and West Point.
TUOLUMNE ANCIENT RIVER OF GOLD
Tertiary Tuolumne River parallels the present-day Tuolumne River from Oakland Recreation Camp in the Stanislaus National Forest to Chinese Camp by Highway 49. There are many gold sites both north and south of this ancient river and near the towns of Coulterville, Jacksonville, Jamestown and Tuolumne.
ANCIENT INTERVOLCANIC CATARACT CHANNEL
The ancient Intervolcanic Cataract Channel originates in Calaveras Big Trees National Forest in Tuolumne County. It crosses the North Fork of the Stanislaus River into Calaveras County. It then crosses the Stanislaus River near Carson Hill, Columbia State Park and Squabbletown. The channel continues in a southwesterly direction a few miles west of Sonora and Jamestown and terminates at the Tuolumne/Stanislaus County line. A considerable number of gold deposit sites exist at each of the aforementioned towns.
ANCIENT RIVERS OF GOLD
Information from www.goldmaps.com