Where to Dredge
The bedrock at the bottom of the river is not the only place you will find gold, however. When the bedrock is deep, there will be clay layers that form at intervals from the river bottom to bedrock.
When compacted, these clay layers can act as a "false bedrock." That is, unless the flood is sufficient to churn up the entire river bottom all the way to bedrock, then the material in the first few layers may be all that moves.
The gold may be heavier than the material in the clay layer, but unless that material is agitated, the gold can't penetrate it. So, the gold will be sitting on the clay layer, or may only penetrate it as far as the overburden will press the gold into it.
Click on Picture to Enlarge
As a rule of thumb, the gold will be in about the top 6 inches of the clay layer. If you dredge beyond this top 6 inches, be prepared to go to the top of the next clay layer (or bedrock, whichever you reach first).
Clay layers will vary in thickness from a few inches to several feet thick. So going to the next clay layer can be quite time consuming. The dredging hole must be expanded to go deeper so as to make removing boulders easier and working in the hole safer (from cave ins).
When working in an area that you know will have clay layers, consider each clay layer "bedrock" and work it like you would bedrock. Once you reach it, work laterally (to the right and left) until you reach the outer edges of the pay streak.
Once the sides of the pay streak are found, you must decide whether to continue on this layer or dredge down to the next layer. But, when making your decision, remember that just because there is a pay streak on this clay layer does not mean there will be a pay streak underneath it on the next clay layer. There may be a pay streak on that next clay layer directly underneath the pay streak of the clay layer your working, but, it may be located to the left or right , or may not be present at all.
Working clay layers can produce good gold, but the best gold will be at bedrock. Try to work areas where you will be able to reach bedrock immediately, or at least only one or two clay layers before bedrock.
Gold Prospecting Supplies and Equipment you can buy now from