Although the California gold rush has long been history, minimal amounts of gold are still available in rivers, creeks and water-ways not only through California, but throughout the country and even the ocean. It does not hold much value because the gold must be concentrated. The source of how the gold first got to California lies in events that occurred 400 million years ago. Geology explains why. California was at the bottom of the sea at that time. The beaches of this land lay in Utah and Arizona. To the west of the Pacific, volcanic islands spewed ash and lava onto the ocean floor. The hot springs on the sea bottom collected big deposits of sulfide mineral deposits.
Around 200 million years ago, the geology was such that titanic forces caused the offshore islands to collide with the North American continent which crushed the rocks from the sea and volcanoes. These rocks, over the course of many, many years became what was to become the Mother Lode of the California gold rush. Rain and snow began to work along the ground into the region of the Mother Lode. Millions of years of geologic erosion brought the water closer to the molten magmas. The higher temperatures caused the stable materials such as quartz, gold, zinc, copper and silver to dissolve. As this water cooled it provided the mineral riches as large veins of quartz with various amounts of gold and silver. Some of these veins emerged at the surface as hot springs such as those in Reno and Carson City.
As time began to erode the mountainous regions, gold and silver were washed into the great valley and made their way into California. Geologists have deduced that much of the gold in the region was a result of natural erosion.