All of this is from surface soil samples which only confirms that there is gold in the area. We knew this already because there was already gold mining going on. This is generally something that you do when you turn up to a totally unexplored area to see what might be there in the sub-surface before you go and mine it.
Just because you find a sample of gold in the surface soil does not mean that there is gold directly underground at that location, or that gold still exists in the area since this area was already mined extensively. This area was glaciated, which eroded all the surrounding bedrock (containing some gold) and spread this signature over the region (but concentrated in the local area), incorporating this into what now exists as surface soil. Chances are that these results represent the remnant gold signature of the vein which has already been mined out by the historical workings. Or you can roll with your story and take a small amount of evidence and blow it up on a big scale.
As someone who knows about geology and sampling - saying that there is a massive amount of gold from soil samples is pushing it. I certainly wouldn't dare make a claim like that.