View of a caisson in the middle of a body of water, which is identified as the Copper River. The caisson is circular and appears to be made of wood. Workers, barrels, ladders, and a smoking chimney can be seen on the caisson. A rope bridge extends out from the side of the caisson. White numbers with notches are written on the front of the caisson to mark the water level. Metal tubing and wires hang from a wooden structure. This structure extends out into the foreground of the image. A group of workers are being carried across the river in a lift attached to suspended wires. A rocky waterfront with three wooden buildings is visible in the distance. Large, snow-capped mountains fill the background of the image.
