A man named Bob Allen wrote a book about his and his partner's experiences in tracking down a Spanish gold diggings. He was very good at deciphering Spanish trail signs and symbols. The name of the book is Forgotten Trails and Devil's Gold;, copyrighted 1991. In this book he tells of different trails he followed and what different symbols meant. The main story of this book is the last hunt they were involved with. The signs they had followed seemed to say the mine they were looking for was cursed and they were told by someone he simply called "The Old Indian" that they should not continue and he, the Indian, left them on the trail. Continuing anyway, they came up to a shear cliff that was across the trail and was insurmountable. They couldn't climb it and couldn't go around. So they backtracked to a small town and had a friend fly in and then fly them back over the area. Point One: that cliff was not on their maps. Point Two: that cliff was not there when they flew back over the trail. They went BACK into the area on the trail and while camping close to where they figured the mine was located, Mr. Allen woke up during the night to see the apparition of an Indian warrior running at him with a lance at the ready. The lance hit him in the abdomen as he fired his carbine at the "Indian" and passed out. His partner packed him out right then to the nearest hospital and Mr. Allen was close to death and the doctors couldn't figure out WHY. He was very sickly for a few years and never got back into the field. I met his niece shortly before I left OKC and asked her if the stories in his book were very accurate or did he take a little leeway in his writings and she said that her uncle did not BS around with his writing; that if he said it happened, then it HAPPENED. I also asked if he would ever publish another book and she said that he wanted to because he'd had a long life of treasure hunting for Spanish diggings and he wanted to write about more of his adventures. But, she then said that she didn't think he'd last long enough to do that.
If you can find this book, buy it. In his stories, he tells of many of the signs he follows and DECIPHERS the signs' meanings. On the inside of the cover there is a note that some names of people and places had been change to protect privacy.
NOW, having said all of that; the question then becomes, "Can a spirit harm you?" In this case IT DID. Also, can a solid rock cliff appear across a trail and be "real" enough to touch and explore? In this case, IT COULD. That mine they were looking for had the bodies of murdered Indians buried there as sentries and one of them attacked Mr. Allen during the night and damned near killed him. The doctors never could figure out what his illness was; much less, what caused him to almost die.