I'm not the most experienced miner but if you haven't found one speck or flake and you know where in a river to look and how to do it, you are on a river that has no gold. Drive down to Colfax northeast of Auburn and try the Bear river. Or the North fork of the American river. Very close to each other. At least you would go home after a day with a penny weight of gold. If you are sure it had gold in it at one time then keep at it, look south of where u are, maybe you are north of the deposit area. Good luck.