Evidence of Historic Mining

Evidence of Historic Mining
One of the best ways to find an area to prospect for gold is to locate areas that the old-timers have already mined. Miners have been actively searching for gold in most of the U.S. for well over 150 years now, and there are likely very few areas that are undiscovered. While there is certainly an opportunity to find undiscovered gold deposits, most of these are going to be found nearby to the areas that have produced in the past.

So how do we identify these places that the early prospectors in an area worked? It is relatively easy to see the telltale signs of past mining, but many new gold prospectors don’t really know what they are looking at. Understanding the historic mining methods that were used can help us determine the likelihood of how and where the gold will be there today.

Dredge Tailings – One of the easiest workings to identify are tailing piles left behind a bucket line dredge. These massive dredges were used to mine the gravels of many rivers in gold districts throughout the west. They are easily identified by their large rock piles left in relatively uniform patterns and rows. Viewed from aerial photos, it is easy to see the zigzag pattern that was left behind. Often there are small ponds throughout the tailing piles as well.

Like all of the old mining methods, these old dredges were somewhat inefficient, so they would miss so gold which can still be found in the piles. They also used screens to discharge larger material, so large nuggets and specimens were occasionally kicked out the back of the dredge, waiting to be found by prospectors today. Metal detectors can be used effectively in tailing piles, but they are notoriously trashy, and it can be difficult to locate gold without dealing with thousands of ferrous iron targets.

Hydraulic Workings – Another method that the early miners used in some areas was hydraulic mining. This involved running high pressure water through a huge cannon called a monitor, to literally wash away a hillside and release the gold that was locked in the gravels. The scale of these hydraulic workings can vary; some are relatively small and were used on small creeks, while many of these areas are massive and can be seen from miles away.

Gold can be found anywhere in hydraulic pits, but some investigation of the area can help you determine the best places to look. If you study the terrain, you can often find the areas where to monitors were set up. There is often an elevated piece of ground, and quite often it will be littered with lots of old iron rubbish. You can visualize the area where to water was washing away material, and locate the exposed bedrock and virgin banks that were just out of reach of the high pressure water. Due to the high volume of runoff produced at these sites that would commonly overload the sluices, hydraulic mine sites was notoriously inefficient at times. There are still plenty of gold nuggets that were missed and still left to be found.

Hand Placering – There are thousands and thousands of miles of creeks throughout the U.S. and the world that have been hand placered. This simply means that the gold was mined without any specialized equipment. The miners simply used picks and shovels to get down to bedrock and find the gold. Many beginner prospectors might confuse hand placered creeks with the larger dredge tailings. The easiest way to tell the difference is that hand worked areas are usually less uniform in appearance, with stacks of rocks and overburden scattered around in random locations. Dredges required a large amount of water to operate, so most small creeks and gulches were worked by hand rather than with dredges, which were generally used in the main river channel.

Creeks that have been placer mined by hand can still hold excellent potential for gold. Thousands of early miners worked by hand, and some were more efficient than others. Often they missed gold that was down in the cracks of bedrock and difficult to expose. Gold was also lost when they shoveled overburden into waste piles on their way down to bedrock. Sometimes there was gold in this material, and it is still waiting to be found today.

Lode Mines – Many of the largest mining operations were lode mines, which were the site of the hard rock gold deposits that fed the placers below. These mines are generally easy to locate, are often marked on maps, and have the telltale piles of waste rock and crushed ore lying around. Tunnels can often be located, although they are often caved in if they have not been actively worked for a long time.

These lode mines can be great areas to search for hard rock gold and specimens still locked up in quartz. Just be aware that many of these old mines are still in operation or located on patented claims so they may not be open to prospecting.

Also Read: Bucket Line Dredging

And: Historic Gold Mining Districts of the U.S.

Drywash Piles/Hillside Prospects – Many of the sites that gold prospects around the west were relatively insignificant. Often they were small outcrops that a prospector did a bit of digging to recover some exposed gold, but stopped after the gold ran out. In arid climates like the desert southwest, prospectors often used drywashers to prospect these locations, leaving behind waste material. The inefficiency of drywashers meant that quite a bit of gold was lost, and remains to be found in those old piles. Sometimes these prospects are located just uphill from a creek or river, and prospectors would pack the material down to the creeks.

Sometimes seemingly small and insignificant hillside prospects can be rich with gold. The old timers did not have the efficient mining equipment that we have today, and they missed a lot of gold. Metal detectors can be a great way to explore these areas, and find gold nuggets that the old timers missed.

Locating old mining areas is a great way to find gold today. While it is certainly possible to locate patches of gold in virgin ground, finding these sites where gold has been mined before is by far the easiest way to recover gold. Identifying the type of mining activity that took place can help you determine where you are most likely to find the gold that was missed, and add how you can best add some gold to your poke today.