But miners did not dream of bricklayer wages. They wanted more. That’s why prospectors were typically testing the waters, so to speak, in search of a vein higher upstream. Let’s assume for a moment that they couldn’t find that ledge of quartz, but the quantity of gold in the stream gravel was pretty good. They were stuck with mining the streambed itself or an alluvial fan where water once ran. That’s called “placer mining.” In that case they needed a way to sift more sand and gravel faster in order to have more gold at the end of the day.
Rockers were boxes into which the miner dumped gravel and sand scooped from a stream bottom or alluvial deposit. At the top of the box was a sieve where the larger bits of gravel were screened out. Below that was an incline set up with a series of bumps or ribs down the length of the box over which sand would run when the worker poured water into the device while rocking it back and forth, the equivalent of shaking a gold pan. A piece of draping canvas helped filter out the gold from the lighter stuff. Rockers were especially useful if the material a miner was working with was partially cemented, meaning sticky clay had to be washed away. A good rocker operator could triple his day’s take over panning, meaning he was up close to what a major general might make.
Still, it was pretty tedious work and the miner was not making the fortune he was dreaming of. A faster production method was called for.
The quickest way to pull gold out of a streambed for one or two men was a sluice running into a rocker. The downside was that you needed a downside. That is, you needed some elevation for water to pick up some speed to wash over the material you were working. Sometimes that meant digging a ditch, which was a lot of work. A sluice was only practical if the bits of gold were fairly large. Gold “dust” would float right out.
A sluice running through a giant could handle 500 yards of gravel a day, compared with that one yard a man with a pan could process. That meant a miner could work material that was a lot less rich and still pull much more gold out in a day.
This sloshing escalation of mining methods could be carried to ends that a single miner couldn’t handle, such as hydraulic mining and large-scale dredging.
No matter the method, the idea behind placer mining was to rinse away the rubble and expose the gold in the remaining sand. It’s a fairly benign operation at the lower end of the scale, but the more material an operation uses the more a streambed or ancient deposit is disturbed. See the aerial below of the windrows of gravel left by the Yankee Fork Dredge.