I was asked to dowse this site for chambers a while back. I found 3 chambers. One north of the other 2. I also found a tunnel between the north/south chamber. No gold, No silver. Then I was told there were 3 chambers there. 2 were correct the north south with the tunnel. The 3rd I marked was on the wrong side of the south chamber.
Art you were correct there is a man made tunnel about 100 or so feet straight down to the first chamber. I later found looking at videos of the people checking the chambers and tunnels that there was dynamite and ready for this a little red wagon!
regards, Tim