Can you help me?

I am a certified diver looking for new hobby or passion. Can you assist me with the following?

Locations of old gold mines fed by rivers and streams dumping into the Puget Sound or surrounding lakes? Is it possible to find changes in lake beds, changes in streams that may have contained a high level of gold? Can these locations be found or plotted to show possible old deposits? Is it probable to reach these deposits by diving? Not looking for a Gold Deposit equal to the Sierra Madre, just a fun hobby...