What Did You See This Weekend?

I went on a field trip into the Central Valley, where we saw California's last operating Yuba Gold Dredge at work. It's a gigantic floating contraption some 70 meters long and 20 wide that scoops up gravel, separates the fine material and sifts that for gold. It's a clanking, roaring, squealing, grinding, whining, thumping machine that would make a grand centerpiece for a Burning Man or a Grateful Dead show—or maybe a big party at the GSA annual meeting. Fortunately, you can get a bit of the flavor from a YouTube video made earlier this month. Can you top that?
_{Yuba Gold Dredge 17, Marysville, Calif. — Geology Guide photo}