Okay, so I built a mining outpost in the iron mine.I took a break from the game. I was getting a little crazy myself. Here I am back.
You missed an important part of the equation:
How about a mine in the iron mine or the gold mine?
Results so far:
Plains mine near starting point: 33-272
Mountain mine: 3-37
Mine mine: 3-10, and the native assigned there keeps disappearing, possibly to the above-ground part of the map that corresponds to the cave.