As an experienced miner and prospector John Chuning might be looking for other things, prior to looking for a pit, open or closed. Given the information that he told others, if true, I think the first thing he would look for would be the trail. That would be the largest item in the list. He might look for a hole or cave that the trail actually goes right through. That would be a pretty good clue that he is on the right trail. Not many trails go through a hole or cave. The next most obvious clue, on the trail, would be the walled up shaft or tunnel. Finding this he would look for the pit or pits directly above the shaft or tunnel. At this point that should be no great effort. During the entire search from finding the trail to finding the pit or pits, I can guarantee he would be looking for tailings or any other signs of mining. The pit or pits, uncovered or covered, would be the last object in his search. Now perhaps he might reverse this process and go right for the 4X4 hole in the Superstitions, but that seems unlikely. I believe it is safe to assume that you did not begin your search by looking for the covered, uncovered or filled in pit or pits. Finding the trail, the hole or cave which the trail goes thru and then the walled up tunnel or shaft would make finding the pit or pits, in any condition, childs play. Of course this assumes that the story or stories are completely true. If it's not there, it is probably in the next canyon over.

When you have found everything, up to the walled up shaft or tunnel, I imagine you will have no trouble finding the pit or pits directly above it, even if they turn out to be 2X2. If you do have a problem feel free to call me, as I have the technology and would be happy to find it. I would only ask for a piece of the ore, the size of my head (which is rather large) for a souvenir.

Anyway, despite all the "Joe Vinegar" in this post, the point is, that the pit would be the last item in anyone's search and if you found everything else it would not be a problem to find the mine. The first qualification in this, is that the story or stories must be true. Have you found the correct trail that goe thru the hole or cave, and the walled up tunnel or shaft yet. If so you are a very rich young man.
Most of this post was in jest, and I hope you take it that way.
Joe