GOLD Placer Mining

Add vechicles like bull dozers, drill machine, front loaders , Wash plants be able to survey for concentrations of fine gold in plain dirt, build wash plants to process into concentrate and then buildings to smelt and futher process , Dirty water would be a by-product and you would have to build settling ponds for the silt to settle from the water before being able to use the water or release it in a river without huge pollution penalties