Gold Is Where You Find It.

Gold is 19 times heavier than water and is predictable in it's movement. The trick is to look in areas that gold, if present, will probably be found.  It takes a good strong flood to move gold and areas where the water pressure slackens gives it a chance to settle.  It is best to observe the flood at its highest to help you locate the backwater areas. 

When you find that layer, I think it is best to sample above and below the layer to make sure your not missing it and then just work the productive layer.  I produce more gold that way, but I get that nagging feeling like I might be missing a nugget. 

There is a hard pack layer all throughout the areas I have dredged that looks like it was scorched and it is like cement.  I have found pickers on it before.  Once you break through it it isn't very far to bedrock.