In Sumpter, eastern Oregon, where gold was first discovered in 1862, the surviving Sumpter Valley Gold Dredge represents the industrial scale placer mining brought to the valley floor. Floating in its own pond, it used electrically powered buckets to scoop gold-bearing earth, processed the material on board, trapped gold in riffles, and dumped waste in long tailing piles. Three dredges worked the district from 1912 to 1954 across more than 8 miles, recovering an estimated $10 to $12 million in gold. Yet the operation was demanding and not always profitable, and the last dredge closed deeply in debt despite near-continuous work.