Within sight of the town of Bonanza is the Yankee Fork Gold dredge. The dredge started operating in 1940 and operated on-and-off in the hands of several owners until 1952 where it was abandoned completely intact in the pond of its own making.
   In its life, the dredge moved millions of tons of rock and traveled over 7 miles upstream from where it started mining.

Dredges are essentially a floating factory with an excavator on the front. This dredge had 72 buckets, each weighing 1100 Lbs. each and capable of carrying a half yard of rock to the mill.
  The dredge buckets would burrow 20 feet or more into the riverbed to reach the rich gold-bearing gravel lying on the bedrock. As the dredge dug, it would be moved about by a series of cables and winches that pulled it side to side and forward to fresh gravel

The dredge would literally dig it’s own “pond” to float on as it moved.

Despite being abandoned for a half century and having the occasional band of hippies residing in it during the 1970’s, the dredge is amazingly intact.  It has been somewhat restored by a group of volunteers who work with the forest service and give tours of the dredge for a small fee.

Cat checks out the control room equipment. The tour guide for this part of the tour told us his father used to be a dredge operator on this machine. As children, he and his brother would lay out sleeping bags in a corner of the control room and try to sleep in the deafening din made by the machinery while their father worked!

This “tattletale clock” monitored dredge operations by keeping a record of the bucket line’s depth.
   Each squiggly line on the clock chart records one “swing” of the dredge bucket line. The jagged swings recorded by the clock show the bucket line bouncing harshly on the bedrock. The  smoother lines show easier digging.
   Since too much bouncing of the buckets on the bedrock tended to break things, the tattletale clock would not only tell the owners how much work had been done in a day, it could show if an operator was doing his job properly.

Our group of 20 enjoyed the tour, which was given by volunteers who either worked on the dredge themselves, or had relatives who had worked on the dredge.

The dredge was powered by a pair of air-started 8 cylinder diesel engines. You can see by the size of the people next to them, just how large these engines are! The engines exhaust through a pair of 10 foot tall, 3’ diameter mufflers and out through the roof.

This is where the money was made: The dredge had 40 sluice boxes (20 on each side of the trommel), and a cleanup table like this one on each side. The highly concentrated ore would be amalgamated with mercury here to recover the gold. Right next to the cleanup table was a small retort used to drive the mercury off the gold and recover it for reuse.  (Private gold ownership was illegal then, the owners of the dredge had to have a special permit to do this!)  They recovered gold was sent via regular US mail to the US mint. (Why not? it’s insured that way!)