A pick and a pan are the iconic tools associated with gold digging. But those aren’t necessarily the most efficient instruments to extract anything of value from the ground. For a faster way to unearth large quantities of gold, prospectors turned to dredges, and you can tour one that remains at the base of the Elkhorn Mountain Range. Sitting in a pond of its own making is a five-story machine known as the Sumpter Valley Dredge (211 Austin St., Sumpter, oregonstateparks.org) that kind of looks like an oversized houseboat crossed with a sternwheeler, only instead of a paddle you’ll find a massive system of pulleys and cables along with a chain saw-shaped arm bearing 72 1-ton buckets. Those containers chewed through the land, scooping rock into the dredge’s belly, where steel cylinders would separate the material by size. Leftover gravel was shot out the back end. It could process 9 cubic feet per minute and operated 24 hours a day, every day, except for Christmas and the Fourth of July, from 1935 to 1954. In its time, the dredge dug up more than $4 million worth of gold and scarred untold acres of Eastern Oregon.