Probably a few areas along that small mountain. A similar looking area I know of has several filled in mines. Along the trail are several small mexican mine markers. In your pics, the trails can almost be seen. Something to keep in mind. I was hunting an area and the weather went to rain, so slow rolling home, on a trail I took hundreds of times, I noticed a cave looking thing near the top of the similar small Mt. I never noticed it before, but I never came through at that time as I would be working another area until dark. Not sure if it was the wet rocks or the time of day, but there it was. The following week I could barely find the location knowing it was there and having lots of pics of it. So, if you get rained out, it may still be worth eyeing the area when it wet. I also found a large 3 similar to Sandy's when the rocks were wet. I didn't notice it previously.
A better quality pic would probably help you with the zoomed in things you could see.
Good luck and happy hunting.