I finally got a chance to test my Magic Treasure Hunting Gadget [MTHG] in the
field. I hiked up to an old poor boy mine not to far from my house and did a scan
across the top and I am pleased and hopeful to say the least.
Slides have all but closed off the tunnel entrance so only a small opening at
the top of the entrance is visible, I peeked inside and from what I could see it
looks like the opening of the tunnel is about five feet tall, It also looked like a
bear had been using the tunnel for a den so I didn't go in and look around.

The
tunnel is in decomposed Granite which is kinda unstable so some shoring was viable
inside the opening. My scan was done on a very narrow ledge about 15 or 20 feet
above the opening, I had hoped I could get an accurate measurement of the distance
from the scan to the top of the tunnel but from where I scanned to the top of the
tunnel was very steep, so I had to make a guess.
You will notice that the ground surrounding the tunnel shows up as red instead
of blue like the scan of the culvert in my driveway, thats because the soil around
the tunnel is highly mineralized, which is probably why they were mining there. The
colors can tell you something about the rock but when hunting for a tunnel what
your really looking for is a difference from the surrounding rock, and an empty place
in the ground is different.
So far I'm happy with what Ive seen the MTHG do, I would still like to scan a
known tunnel thats deep, maybe 100 feet or so, and if I could see that I would feel
confidant I could see a Spanish tunnel.