The old reliable 2" at work sampling a small gulch.
The Gold Rush program on the Discovery channel is one of the most watched shows on television. For good reason, who doesn't like a show about finding gold, but have you paused to wonder whether they're actually making any money at it?
It would appear by adding up their costs versus the amount of gold recovered they're losing money. That's big equipment, and big gas bills. The labor costs are likely the largest portion of expenses, but at the end of the day it's unlikely they make money from their mining.
There's a simple math problem in mining and it works like this: recover the most gold you can while moving the least dirt you can.
For comparison, the old hydraulic operations recoverd about 4 cents per cubic yards. Factoring for inflation that would be about $1.00 per cubic yard today. Based on the information from the Gold Show it appears they are recovering about $1.65 per cubic yard. On average, based on usinga 4" suction dredge, on a normal paying claim a gold dredger recovers $55 per cubic yard. This is assuming a fairly lean claim which returns two pennyweight a day.
That's about 50 times more gold per cubic yard moved. In other words you can move 50 times less material and do the same from a revenue standpoint, but in reality you're doing much better when you factor the expenses. Your expenses are pretty slim, especially if you're dredging alone.
Dredging is the most efficient way to recover gold. The forces of nature have concentrated the gold within the bed of the stream for you, and in many cases the river has stripped off the overburden for you. We actually remove very little overburden compared to other mining operations.
Its this concentration of gold we're all looking for. There are a lot of books written about dredging, but they all come around to one main point: sample.
I own several sized dredges: a 2" backpack; a slightly larger 2.5"; a 4" and a 5". The dredge I most often use is the 2" because I'm sampling. I'll pack the 2" into new areas, punch holes up and down a creek and make some calculations on the gold in the gravels. If I'm still waffling on it, I'll swap over to the 2.5" and go a little deeper, move more material and check again. You'd be surprised how much more material a 2.5" can move than a 2".
Why two little dredges? Packing a 4" or 5" in to a remote canyon is about the same amount of work. The only real difference is the weight of the engine. All the other parts about the same amount of misery to pack in, and are exactly the same number of trips. If you work alone, like I do, then all that goes on your back. Before I pack in a bigger dredge I'll make sure it's worth my while.
A 2" dredge I can pack in one shot. Everything on my back and in my pack including enough gas to run for the day and a wetsuit. The 2.5" takes me two trips. I have the same engine for both the small dredges, but the 2.5" has bigger floats, bigger hose, heavier riffles and is just too much to carry in one trip. I use the Dahlke 2.5". It's a neat little design for working by yourself. It has the sluice integrated with the floats and allows you to very rapidly attach the engine, so it's fairly portable and quick to set up.
If you've never run both sized dredges I can tell you the 2.5" moves more than double the amount of material a 2" does. I can punch through overburden as far as my arm will reach, and I can pretty quickly hit bedrock. With the 2" I don't even think about moving overburden, I'm either in the cracks, or in very thin overburden. Unless you want to chuck pebbles all day long the 2" is pretty limited, but it is way better at sampling than a pan or sluice box.
The much more capable Dahlke 2.5" in a sampling operation
Does it work? Yup. One day, many years ago, I was on the Stanislaus and had packed a good ways down river to a club claim of which I belonged to at the time. It seemed to me if I could get away from the crowds I'd do OK. So I packed about 3/4 mile downriver and set the 2" up and got to work. I punched a few holes and moved, punched a few more and moved (found some really nice nuggets by the way). Finally I hit some unworked pack, which if your familiar with the Stanislaus is a really, really nice thing to hit.
I'm just going to town with my little 2" and having a great day when a guy comes walking down the river. I'm in the middle of the river just letting the little 2 cycle buzz away and chucking rocks. He's looking at the rocks and I knew I was busted. We all know what unworked pack looks like, so did he. He leaves and a few hours later back he comes carry a 8hp dredge engine. He leaves and a few hours later comes back with another. By the end of the day he had all the parts for a 6" and was planning to just set up on my hole when I left.
That was the end of my club claim days. After that I only went to open land, did my own sampling and staked my own claims. I wasn't going to do someone elses work for them.
Of my collection of dredges, if I had to pick only one it would be a tough choice between my 4" Proline and my 2" Keene. I like the Dahlke well enough, but I've got some great memories, and great gold with the little bitty 2". I imagine if I ran it all summer I'd end up with more gold than most dredgers do, but it's research, planning and sampling.
If you want to find more gold, then consider how you're sampling. If it takes so much work to move your big dredge, then get a smaller dredge you can easily move and cover more ground sampling. Then move the big dredge.
Good luck out there.