The problem is that extracting gold from hard rock is often a lot more difficult than processing placer gravels. Still, there is some very high-grade ore out there in many old mining areas.

After burning more than 350 square miles, the Carr Fire near Redding, California, was finally out. Luckily our home was spared, and I had the opportunity to go metal detecting in burned areas previously too overgrown to access.

Hearty trees, shrubs and plants are a product of the soil conditions in which they grow, so it makes sense that roots near an ore deposit will take on nutrients containing metals if they are present.