kebac:
That "O" is a little odd, but there are a lot of things in your photos that will seem odd until you learn to decipher them. You will now have to do a lot of research into the KGC and the James brothers. Start that research here in the section Marks and Signs. Read everything in this section whether or not you think the post has anything to do with your needs. Ancients symbols became Indian symbols then Spanish symbols and finally KGC symbols. Some were use as is and others were modified by the later users. Be prepared for a lot of notekeeping and photo taking. But, it's really, really interesting. I would suggest thoroughly checking that cave. For someone to go to the trouble of burying it, it must have some very important information and possibly some valuables hidden there. Use a good metal detector to check the floors and walls of the cave and the area outside area. If you get a signal, dig carefully and do not move any metal targets (or buried marked rocks). Their positions could be very important.
Read everything posted by Old Dog, rangler, DanielLindsey, dsty, Blind in Texas, Texas Jay, Desertmoons, and Rockhopper2, to name just a few of the most knowledgeable folks on this forum. There are some others, but these people came to mind first and I'm sure I've missed some of the good ones. There are also a very few naysayers who will put down everything posted. You will quickly learn who they are and will have to decide whether or not you'll allow them to steal your dream.