If the material drops down out of the hopper too fast, it can overwhelm the riffles and you can blow the gold right out. If it runs too slowly, the riffles can clog up and the process is too slow.

I have seen many samples taken originally with an eye toward getting the highest grades possible, but later someone claims that those results represent an average grade of the whole gravel deposit.

There are currently about 170 commercial-scale placer operations in Alaska. Most of these are small operations with just a few people working; they are often family affairs that operate seasonally only during favorable weather.

This wash was not far from where I once dug a half-ounce nugget, so I knew there was gold in the area.