Suction Dredging in Alaska in October

The setting for this series of pictures is 40 miles south of Anchorage on Crow Creek. The Kenai Pennisula is very mild most of the year which makes it possible to operate a suction dredge from April through October. Many of the streams are glacier feed which means they are silt-laden during the summer months and run clear during the winter months. Therefore, the winter months tend to be more favorable for dredging, not only because the water is clear, but also because the water level drops resulting in less current. The first order of business is putting the equipment in place. Although Crow Creek is fairly accessible, getting the equipment in presents quite a challenge as demonstrated by the picture below.
It is extremely dangerous trying to carry equipment down into a canyon on your back so the preferred method is to string a rope or cable from the top of the canyon to the bottom and using a pulley, lower the pieces of the dredge to the bottom. This is obviously a two-person operation. This picture was taken October 6th with the weather being ideal for dredging. However, it would not be until the following weekend that our vacation time begins and we are able to start dredging. The weekend is spent pre-positioning the equipment.
The suction hose is lowered using the same technique. In this picture one can see the frame and floats resting at the bottom of the canyon, on the edge of the stream, 100 feet below.
Once the equipment is lowered into the canyon it is assembled and floated downstream to the location we have selected to begin operations. The daytime highs are in the 40s and the night time low reach about 25 degrees. For this stream the conditions are ideal. With these temperatures the glacier run-off stops. If the day time temperatures get too high the glacier begins to melt and the water becomes cloudy. This doesn't present a major obstacle but I like to be able to see the gold entering the nozzle of the dredge. Clear water makes the whole experience more enjoyable. In addition to clear water, the level of the stream drops, and one does not have to deal with operating in fast water. The weather, this weekend, is ideal.
Wouldn't you know - the day we begin the operation it snows. The temperatures are still favorable and a little snow presents no real problems. As long as the day time highs stay above 25 degrees and the night time lows stay above 10 degrees the conditions will remain good. The only difficulty is climbing up and down the canyon wall.
In full operation, we both go to work in the pay streak. Rocks were stacked up, across the creek, and downstream from both dredges. This serves to slow the flow of water making it easier to operate while allowing aquatic life easy passage. The pool that is created by the suction dredge provides a resting spot for fish migrating upstream. There are no fish present in Crow Creek where we operate, however. Downstream from us is an 80 foot waterfall making it impossible for fish to migrate past. Never-the-less, the points made above holds true for any stream that habors fish.
In the center of the picture, below, you can barely see my son, Brian, on his climb half way up the canyon wall. This is the exact same spot we lowered the equipment from the week before. What a difference a little snow makes. The footing and the rope become very slippery under these conditions. Slow and easy is the name of the game.
By day three the temperatures have dropped to 10 degrees for the daytime high and -5 to -10 during the night. Under these conditions 2 inches of ice forms over the dredge pool made the day before. Before beginning operations, one must break up the ice from around the dredge.Under normal conditions one is limited to about three hours of operation each day. It takes at least two hours to clear the ice and prepare the equipment. The water temperature is right at 32 degrees which causes ice crystals to form on the bottom of the stream and at the pump intakes. Much time is lost freeing the intakes of ice. In addition, the sluice box riffles, concentrates, and carpet freeze almost instantly when the dredge is shut down. As a result, first order of business is to release the riffles and slide the carpet and concentrates into a container under the water to be processed after the intake hoses are removed and pumps drained. This picture shows Steve in the process of clearing the ice.
After viewing these pictures you may ask if it was all worth it. The answer for the more hardy is YES! For me the ordeal was too much and I pulled out after the snow and cold weather hit. Steve remained to the bitter end, ignoring the worst that mother nature could throw at him. He was rewarded handsomely for his endurance. I would be out of place to tell you just how much gold Steve collected but I will tell you that for every four hours of hard dredging in this spot one will recover between 1 1/2 to 2 1/2 ounces of flake gold.

Last Update: 3/3/2007

Web Author: Rich Lampright

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