Which Streams contain gold? Generally speaking, streams that are most likely to contain gold must have four characteristics.
1. They should be unregulated (not dammed).
This factor is important because this technique is based on the spring flood churning up the minerals found in the streambed. When this is done during the spring flood, the gold and other dense materials fall to the bottom of certain areas first. This concentrates these valuable minerals which allows prospectors to find them.
2. They should be in a mineral rich area
Mineral Rich Area: A good indication as to whether you are in a mineral rich area is to look at the rocks exposed by the stream erosion and highway cuts used in road construction. Virtually any place that the rocks show a non-sedimentary layering will probably be an excellent place to look. This mineral layering is very infrequently level. Many times the rock layers appear to bend and incline. Quartz is commonly found in parts of the layering along with feldspar or other identifiable minerals. Consult field identification manuals for a more specific description of these minerals. They are common and can be easily identified with a little research.
TIP ---> Another indication of a mineral rich area is the presence of black sand. Placer gold is usually found with black sand but the presence of black sand does not necessarily indicate the presence of gold.
3. They should fall through enough elevation to cause sufficient churning in the spring flood
As discussed earlier, gold is extremely dense. If the stream in which you are looking is slow moving and flat, the dense material will have settled out far upstream. As the meandering stream makes its way, it travels in a lazy, snake-like manner, twisting one way then the next. These rivers will provide you with little success. Rapids and waterfalls and white water are indications of quick elevation drops. The spring flood will churn up everything in the river's expanded boundaries.
4. Stream path and rock formations facilitate the deposition of the dense materials (gold, lead, iron, mercury etc.)
As mentioned before, placer gold settles in specific areas of a streambed called pay streaks. These pay streaks are most often found where the water flow slows down significantly. They may also form along a path, which follows the shortest, straightest path down the streambed at high water. As the Spring flood recedes, the deposits can be left some distance above a low, common summer water level. When looking for a good place to search, imagine what the river would have looked liked during the flood (better yet, go take a look if you can get there).
Most streams do not travel in a straight line for very long either horizontally or vertically. The inside of the bends and where the stream levels out after a steeper run are good places for pay streaks to form.
Another good spot to look can be found on the downstream sides of large boulders and other obstacles. These create an area where the flowing water slows down for just a short time. The highly dense materials can be concentrated here.
Other obstacles include bedrock ridges and large fallen trees. The obstacles can be even more productive if they are in that shortest, straightest path down the streambed. Pay streaks may take several years to form so the best obstacles to investigate are those which appear to have been there for a long time. The best rock formations that help the prospector are those that trap dense materials that are flowing by during the flood. These formations can be best described as exposed bedrock with small, near vertical fissures. Smooth, well-worn bedrock is almost never productive.
Where to look for gold:
Gravel bars usually found on the inside of the river bends - especially newly formed. Although the gold here is mostly small flakes to very fine, there sometimes is a lot of it.
Where streams level out after a steeper part such as downstream of rapids or waterfalls.
Small streaks of gravel laying on the bed rock (but you will need some sort of sucker to retrieve it if it is underwater).
Downstream sides of large boulders and other obstacles which because of size or other factors appear to have been there for a long time.
Pot holes or cracks in the bedrock. ---> TIP: In popular prospecting areas, the large, obvious cracks have most likely been cleaned out many times. Look for lines of moss running along the bedrock. There is almost always a small crack under the moss and these cracks can contain a surprising amount of gold.
...and speaking of moss: Moss and grass roots near the riverbank.
Highbenches. As a stream cuts deeper into a canyon, it can leave patches of gravel high on the canyon wall. These are called benches.
Look for round or rounded rocks well above the present high water level. Round or rounded rocks have lived in a river at some time in their lives. Always keep in mind that these are the most likely places to find gold.
There is an old saying: "Gold is where you find it." What this really means is, you may find a spot that looks perfect and not find any gold at all or you may find a spot that looks like it would be barren but you find a "bonanza." Just try to keep your mind open to all possibilities.