Tfinder:
There is a story going around that certain KGC info was stolen and many markers were mutilated; such as a turtle having his head knocked off. That sounds good and may be right, but there's no real way to prove that happened OR the Spanish did it themselves. Many KGC trails follow sections of Spanish trails which follow Ancients' trails, etc.
Old Dog has shown how the Spanish AND the KGC hid symbols within the pictographs of Native Americans. Now THAT would sure take some study to be able to spot and OD, rangler, and a few others on this forum have made that study and have almost an encyclopedic level of knowledge on the subjects of the different symbologies.
You wrote that sometimes you'll end up back where you started before you know it. In those cases, you've missed an important sign on the trail that would have taken you on to the final trail. Old Dog has written many times that the symbols will get smaller as you get closer to the "hide". He mentioned finding turtles that were only about 2 inches in diameter. Blind in Texas posted a photo of a map of a river system no bigger than your thumb. Then, there's the subject of false trails. LOL Yep, those Spanish were kinda sneaky at times. They'd even put deathtraps on false trails and fake deposits.
There are some truly AMAZING things "out there" and I envy you folks who are able to get into the field and see them first hand. I'm thinking that all of the things found and photographed so far are just a small portion of what's all out there, yet to be discovered. I've see photos of faces on stone that are so detailed and life like that you'd think they were PhotoShopped into the picture, but they were / are absolutely real and genuine. They look like someone's face was photographically applied to the stone. Those are part of the Ancients' monuments and certainly are NOT Spanish and even less connected to the KGC. The Ancients had technologies that are still unrecognized as their's and most archies wouldn't believe, anyway.
While you're in the field, you have to look for signs and symbols at LEAST as well as you watch for sneaky snakes. LOL
Good luck to ya.