Mining for Gold

In the alluvial phase of a gold rush, miners use wooden sluices that diveert streams and river beds. They can shovel gravel into it, the force of the river ad washes it for them, and then they can pick the gold out of the bottom. But by 18 53 there's a transition to what's called hydraulic minon am. And this is a different scale of technology but no less simple. The challenge with hydraulic mining is is twofold. It's incredibly expensive, and you need to be able to buy the equipment for it. There are even advisories on california rivers that you shouldn't eat the fish because of methal mercury in their bodies