The buddy that I helped used a powered Dredge setup. There is a fair amount of restrictions on when and where you can use that type to prevent any silt being covering up any fish eggs.
I got pretty damn good at sniffing out honey holes around rocks and bends in the river or Creek.
I Can tell you that gold fever is frigging real! It was wet suits and snorkels for the most part. That melt water was frigging cold! That gold fever would make you stay in there long time! But a quick look at Sparkles in the ripples with just warm your little heart!
A few years ago the buddy that I helped got killed by a grizzly in the spring in Alaska. They didn't find much him.