Here, where it was retired from service in 1954, rests the wood and steel monster that chewed up and disgorged 6mi of the valley floor, sifting through vast quantities of gravel and dirt for gold. It cost $350,000 to build in 1935 and, over the next 19 years, removed about nine tons of gold, or approximately one cubic yard. At then-existing prices of $35 an ounce, that amounted to some $4.5 million worth. Powered by electricity, the dredge floated in a pond of its own making. A chain of buckets brought a steady load of rocks and soil to the surface. Everything larger than three-quarters of an inch was dumped out the back end; the smaller material was run through sluice boxes that trapped the gold. Ironically, a big nugget like the five-pound Armstrong would have passed right through, undetected.