Flooded Out of Crow Creek - 5/15/99
A very interesting weekend, and not altogether unanticipated. The weather this spring has been unusually cool, and very late snows have left large quantities of snow at lower elevations. What I feared might happen was that the weather would turn warmer, and all that snow would melt quickly. Well, the weather has turned sunny, with temperatures in the 60's. This is nice, as the snow is going away, but it has brought my dredging operation to a sudden halt.
I headed down into the canyon at Crow Creek Mine, and looking down at the waters below, I knew I had problems ahead. The water had come up to over twice the volume of the previous week, and the clarity of the water had decreased considerably. I proceeded down the creek, and saw my dredge sitting in fast water, and with a decided tilt to one side.
High water, and sinking dredge!
I normally do not worry about rising water all that much. I often leave my dredge floating and tied off in the creek. I did make a mistake the last weekend, however, and I can attribute it to wishful thinking that the water would stay low for awhile longer yet.
I usually tie my dredge off in the pool I have created by working the dredge, which keeps it out of extreme currents if the water does come up. You can see in the photos above that although the water above and below the dredge is boiling, it is relatively calm around the dredge. I then tie the dredge off to a couple of points upstream, and allow the dredge to float up with the rising water.
The mistake I made was to leave my hose coiled in the bottom of the dredge hole. In normal situations this is okay, but not a good idea if the water is possibly going to rise. I usually worry that the currents from rising water may sweep the hose downstream, thereby pulling the dredge to one side and possibly causing a problem. When I anticipate that this may be a problem, I usually tie the nozzle high above the creek along a rope. When the water is evacuated from the hose, it also floats and acts as another anchor line.
I left the hose in the dredge hole, but what happened was something I had never foreseen. When the water came up, the front of the hole gave way. Rocks and gravel poured into the hole and buried the suction hose. The dredge was then anchored to the bottom of the creek! The water continued to rise, and the front end of the dredge was pulled below the surface of the water.
Several things saved my dredge from sinking. First, I plug all the drain holes in the top of the floats. Each of the four marlex float modules supporting the dredge has an open hole in the top. These holes keep the floats from expanding and contracting due to temperature and altitude variations. They also act as drains for water that may enter the floats, though this is most often through the holes themselves. I use boat style drain plugs, the type with a little brass flip on top, to plug the holes. This helps keep water out. The floatation modules on this dredge are more than ample, so even if a module fills with water, the dredge will still float, but if two fill, the unit will most likely sink.
I also run my anchor lines high, and the right hand photo shows that the leading anchor line runs steeply upward, helping to exert extra upward pull on the front of the dredge. This helps in situations such as these.
Finally, I got lucky. If the water had come up higher, it simply would have submerged the dredge to the point where it would have sunk. The float plugs are good, but not perfectly watertight, and so the unit will sink eventually.
I surveyed the situation, and decided that I was done for this spring. If the water was this high at 8AM, then it would just get worse as the day warmed. I could continue dredging, but the visibility was declining rapidly, and the current would be much harder to deal with. The diversion dam I had built the weekend before was totally submerged. Since I am doing this for fun, and since the gold will be there in the fall, I pulled the dredge out of the creek. I'll pack it out in the next couple of weeks, when the snow melts a little more.
5.81 ounces of gold from Crow Creek
And so, an abrupt halt to the spring dredging at Crow Creek. The final take for the seven days spent (five days dredging) was 5.8 ounces. This works out to 1.16 oz. per dredging day and 0.83 oz. per day for the trip as a whole. The 25% I pay to Crow Creek Mine comes to 1.45 oz., so I will be left with 4.35 oz. for my efforts. This equates to 0.87 oz. per dredging day and 0.62 oz. per day for the trip as a whole. Not a bonanza, but not bad considering that I did not get in full days in several cases.
The gold breaks down into 10% larger than 1/8 inch, with the largest nugget weighing 27.2 grains (1.13 dwt.). The less than 1/8" (8 mesh) but larger than 1/14" (14 mesh) size is typically used for gold nugget jewelry and equaled 33% of the gold. The gold less than 1/14" (14 mesh) is generally too small for jewelry use and can be considered fine gold from a resale point of view. This equaled 57% of the gold, or more than half the total weight.
So what does a flooded out gold dredger do? He goes metal detecting! Sunday morning I took my White's Goldmaster 3 to Crow Creek to look for nuggets for a few hours. The snow is still covering most areas, but cut banks are exposed and so providing a few detecting opportunities. Most of these areas have been scanned on the surface before, but I was not in the mood for serious digging, so I set about scanning the surface for missed nuggets.
I was not having much luck, so crossed over the creek to try some exposed banks I saw. This bank has old tailings perched over the gold poor "blue layer" of material. This is a thick layer of clay-rich material that overlays bedrock. It is relatively fine-grained and mixed with small rocks. It does contain gold, but usually only dust and fine particles. It is overlain in turn by a "brown layer" of streambed material that is a rich yellow-brown color, and mixed with larger round rocks. This is the layer that produces the larger nuggets. The old mining operations worked most of the brown layers and quit when they hit the blue layer. The top of the bluff in this photo is the top of the blue layer. Often gold can be found directly on top of the blue layer where it was left by the washing action of the old mining operations. I have found gold in the past on some of these exposed bluffs where the gold on top of the layer erodes out and slides down the face of the bluff.
Detector on steep bank
I worked this area for a short while, finding a few nails. I then got a signal, and there was a small gold nugget. The White's Goldmaster 3 is a 50 kHz machine that is quite sensitive to small gold. The nugget is pictured here in a close-up, but is actually very small, weighing about 1 grain. This extreme sensitivity to small gold has made the Goldmasters very popular in Alaska. I have had lots of success with my Goldmasters at Crow Creek in the past.
1 grain nugget found with Goldmaster
Meanwhile, my friend Will Holden was upstream a short distance trying his new Minelab SD 2200D detector. This is a very powerful detector that lists for $3495, so you do not see very many of them. It excels at punching through very mineralized soil to find larger nuggets, but is not very hot on small nuggets. It would not have found the small nugget the Goldmaster located with no problem. Still, it's exceptional depth on large nuggets in mineralized ground makes it a machine I am thinking about purchasing.
Will started yelling and waving at me. I hurried up, and saw one of the happiest people on the planet at that moment. Will had turned on the detector and immediately found a piece of iron trash. The second target was quite strong, and turned out to be a nice two pennyweight nugget (1/10th ounce) found 50 feet from the trail in a heavily searched area. His feeling was other detectors would have found it, and that everyone had simply missed it. It is the largest nugget Will had ever found so far, and his hand literally shook from his excitement as I took the photo below.
Will's nugget, found with Minelab SD 2200D
I searched awhile longer and dug numerous fragments of shell casings and lead pieces from bullets fired into the hill in the past. Spring cleaning chores called me home early, but I will return next weekend for a more serious detecting expedition. So ends my weekend of mining, with one small nugget to show, worth about one cent. Such is the life of a gold miner!
~ Steve Herschbach
Copyright 2000 Herschbach Enterprises