Sluicing & High-Banking
When you're ready to move more gravel than a pan can handle, a sluice is usually the next tool you reach for. Instead of working each scoop by hand, you let moving water and a riffled trough do the sorting. A sluice box is just an inclined channel — water runs down it, pushing the lighter sand and gravel through, while a row of riffles slows the flow to create quiet pockets where the dense stuff settles. Gold is roughly seven to eight times heavier than common quartz sand, so it sinks into those low-energy zones and stays put while the rest washes away. A high-banker uses the same trick but feeds the box with a pump, so you can set up away from the water's edge. One thing to hold onto from the start: moving and disturbing streambed material is heavily regulated, and the rules vary widely by state and by agency.
How a Sluice Works
A placer deposit is a natural concentration of heavy minerals in stream gravels — gold gathers there because of its weight and its resistance to corrosion. A sluice recreates that sorting and speeds it up:
- Water flowing down the slope keeps the light material suspended and carries it off the lower end.
- Riffles — bars or angled obstructions across the channel — create small eddies and low-pressure pockets behind each one, where the flow slows.
- The heavy particles (gold, black sand, garnet) settle into those pockets and behind the riffles, while lighter sand and gravel tumble onward.
- Matting or carpet under the riffles — miner's moss, ribbed rubber, expanded metal — catches the fine flour gold that would otherwise slip away.
Your pan never leaves the picture: it stays the simplest way to check material and finish a concentrate, while the sluice handles the bulk volume the pan can't.
Setting It Up
Good recovery comes down to balance. Too little water and the box clogs with gravel; too much and the gold blows right through.
- Classify the feed first. Screening out the oversized rock keeps the box from packing and lets the fine gold reach the riffles.
- Mind your slope. A steeper pitch moves material faster — handy for clearing big gravel — but it can flush fine gold; a gentler pitch holds gold better but clogs more easily. Adjust to your material.
- Watch the water flow. Aim for a steady, even sheet that keeps light material moving without bouncing your concentrates out. A rolling "boil" just behind each riffle is the visual cue most miners learn to trust.
- Feed slowly and steadily rather than dumping. Let each charge work through before you add more.
High-Bankers
A high-banker — sometimes called a power sluice — is a sluice fed by a gas or electric pump and hose, recirculating or drawing water so you can work a bench, terrace, or dry bank some distance from the stream. That reach is its gift: it lets you process old high gravels a stream-set sluice could never touch. But motorized and pumped equipment crosses an important regulatory line. Many agencies treat hand sluicing very differently from anything motorized, so a high-banker may trigger notice or permit requirements that a hand sluice does not.
Cleanup
- Stop feeding, reduce the flow, and carefully lift the riffle tray so you don't lose concentrates.
- Rinse the matting and riffles into a tub; that captured "black sand" is where your gold is hiding.
- Pan or further concentrate that material down until the gold is in your hand.
Know the Rules Before You Run Water
This is where honesty matters most, and I won't dress it up. Disturbing a streambed is not the same as dry panning, and the rules differ by land and by state:
- On most BLM and Forest Service land, panning and hand sluicing that cause little or no surface disturbance generally need no permit — but using a small sluice or rocker box can require a Notice of Intent, and a suction dredge or motorized equipment can require a Notice of Intent or a Plan of Operations plus state water-quality permits.
- Public-land collection and prospecting are restricted in many areas — developed recreation sites, active mining claims, wilderness, and lands withdrawn from mineral entry.
- Suction dredging is the most tightly controlled method of all, and it's outright prohibited in some states. In California, the use of motorized vacuum or suction dredge equipment is currently unlawful in rivers, streams, and lakes, though nonmotorized panning is not restricted.
Always confirm the current state and federal rules with the agency that manages the specific ground — a BLM field office or a Forest Service ranger district — before you put a sluice or high-banker in the water.
In Lodester
Lodester maps the hydrology, geology, public-land boundaries, and active mining claims that shape where placer gold is likely to have concentrated, helping you focus on favorable stream reaches and gravel benches. Remember that favorability is never a guarantee of gold, and a favorable map cell tells you nothing about who else holds rights there or whether your method is allowed. Before you work any site, confirm the land status, check for active claims, and verify that your specific method — hand sluice, high-banker, or anything motorized — is actually permitted on that ground.
This page is general information, not legal advice. Regulations change; verify current state and federal (BLM / Forest Service / state agency) rules for your exact location before sluicing or high-banking.