What determines the amount of gold is the contents of the mountain above. If water is running over an outcrop of gold, no matter how small, bits of it will fall with the water. Those bits will then fall to the bottom (there is usually a well - dug out of the spot where the waterfalls due to the force of the water). If you know gold has been found there before, fine. Since the United States has been scoured by prospectors for 200 or more years, chances of finding a new deposit are slim. Google the area with the word "gold" and see what you can find. However, new discoveries are made in the United States on occasion. Besides that, you will probably find some interesting stuff folks have dropped there. I never pass up the chance to pan/dive to see what's there. Make sure you are with a companion if you do this - buddy system for safety.