Consider a sluice box, similar to that described in the Sluice page, mounted on a 4-legged stand that gives the sluice box the correct slope. Then, mount a box (called a Hopper) at the top end of the sluice box that gravels are shoveled into. In the hopper, put a “grizzly” which is a series of rods sloping in the box that will filter out larger rocks. Also in the hopper, put one or two “spray bars” that shoot a spray of water onto the gravels that you have just shoveled in. Add a gas engine with a water pump and some hoses to get the water from the pump to the spray bars and you have a High Banker.
When you shovel in gravels into the hopper, water sprays onto the gravels. Anything that is small enough to drop through the Grizzly enters the top end of the sluice box. Anything to large to fall through the grizzly falls, or is scraped of with a shovel, into a pile directly behind the rig.
When the smaller gravels fall into the top of the sluice box, the water from the spray bars begins washing out the gravels just like in a regular sluice box. The sluice box has riffles just like a sluice box. In fact, High Banking is often called “Power Sluicing.”
Just like pans and just like sluice boxes, High Bankers come in a large variety of styles and sizes. The small High Bankers often come with a pack frame so the high banker can be backpacked to remote locations. The largest high bankers often are a combination of dredge and high banker, giving the recreational prospector the option of high banking or dredging.
Differences in riffles, spray bars, engine-pump combinations and hose all contribute to a seemingly infinite selection of high bankers. I suggest getting the largest High Banker-Dredge combination you can easily handle and can afford.
High bankers give you the ability to bring the water to you work site. Sometimes, gold bearing gravels are located some distance away from a water source, or the water source is not conducive to using a typical sluice box. The high banker pumps water from the water source to the worksite, so you don’t have to carry buckets of gravel back to the creek.
High Bankers are an excellent way to get involved in recreational prospecting. High bankers are moderately priced, come in pieces for easy transport, and are very efficient.