Gold Mining Techniques

Humans have mined gold for centuries, but not until the mid 1800s did it start to develop beyond just chipping stone out of rock when shiny veins were found in the ground. In fact, since the first gold miners stomped around in cold California rivers in 1848, gold mining has evolved from a collection of pans and spoons to a complicated modern digging and sorting process. Of course, the old techniques are still an option for most hobbyists and entrepreneurs; just don't expect to get rich very quickly looking for gold flakes all day long.

Basic Mining: Gold Panning
Gold panning is probably the most primitive form of mining that exists today. It is essentially what it sounds like. A miner lets the river do the digging, using a large pan to dig up river sand to sift for gold. The pan is filled with river sand and then drained slowly. With the water just about emptied, the miner can shift the pan back and forth, using the sun to catch the glint of any gold flakes or pieces in the river sand.
This process puts the power of gravity to work. Gold, a metal, is heavier than sand and gravel, so it will eventually move to the bottom of the pan. Once the lightest sand and gravel are swept away, any gold present can be picked out of the pan, and the process starts again.
Typical spots in a river for panning are calmer pools or areas where the river turns and creates pockets. Sand and gravel, which can harbor bits of gold, tend to accumulate in these pools. However, keep in mind most river water is cold, so you can freeze your legs very quickly by standing in the water. Waders will provide some valuable protection.
Advanced Panning Via Mechanics
Since panning is such manual, back-bending labor, river miners became creative with their work. To this day, somewhat-automated forms of panning work faster than a regular pan. These include tools called the cradle, the rocker and the Long Tom.

Similar to their names, the cradle and rocker use a box to mine for gold. Water runs through the box, filling it with sand. It is then rocked back and forth, sifting the dirt with a filter on the bottom, and the gold is left behind. Because of the design, the rocker and cradle are not one-person tools.

The Long Tom was a technological advancement on the rocker/cradle approach, providing more capacity and better results. This tool uses a much longer, rectangular box with a filter on the bottom. It was designed with a downward angle, allowing water to be carried through it by gravity. Again, the process involved depositing dirt, using the water to break the dirt apart, rocking back and forth, and sifting via a filter.
River Damming: An Ecological No-No
In the early days of gold-mining, river damming was quite common. However, it results in significant damage to the immediate river area, so today it is prohibited just about everywhere due to environmental concerns.

River damming provided a man-made pooling effect of river water and sand. The concept was to essentially stop river flow so the dried-out river bed below the dam could be harvested for gold more easily. The harvesting went on until the winter rains made rivers strong enough to break dams, and the cycle would begin again the next summer when the rivers receded. Because these efforts involved so much manpower, river damming companies were created to manage all the workers and equipment.

Again, river damming is simply not allowed today. Most hobbyist gold mining areas are in state or national parks, and any damage to a river or creek could land a miner in serious legal trouble.
Going Underground
Unlike the river methods, true mining involves digging. Although early miners would happen by chance upon gold in a cave and start digging, early modern mining purposefully dug straight down in areas believed to be gold heavy. Once a vein of gold was located, the digging would run horizontally along the vein until the gold ran out. This was dirty, dark, hazardous work.

Many times gold is found inside chunks of rock, and brute force is required to release it for harvesting. To accomplish this, miners developed ore-crushing, a method in which rocks showing signs of gold were crushed with machines, weight and leverage. This ore-crushing, however, was a noisy business and eventually was abandoned for more efficient mining methods. The last ore-crushing outfit in existence only runs on a gold-discovery holiday (Founder's Day in Georgetown, California) to show tourists how the operation once worked.

By the 1900s gold mining had become a sophisticated process. Eventually, large-scale productions resulted in open-pit mining performed by hundreds of people. Additionally, underground mining has been augmented with digging machinery, which can find large veins of previously inaccessible gold deposits deep under the earth. So, in some respect, gold-mining has come full circle, starting in ancient times with caves and ending in modern times with professionally drilled and dug tunnel systems.
Conclusion
Gold mining continues to be both an individual and business pursuit, and hobbyist mining is seeing a resurgence these days thanks to the bad economy and the high spot price of gold. That said, few get rich from finding a piece or two of gold. The big business approach is where the profit is in mining. But try telling that to someone who's just found a few flakes