I sure don't know those types of details. The cave or hole could have had a very narrow opening and then widened so that three people could stay in there. I'm sure that when Chris Thomas refers to the searchers not being able to sleep now because they didn't find Elizabeth and she could hear them calling her name, one of them is her uncle, Dave Smart. I know that he did everything in his power to help find her, including searching for her in the mountains. He almost lost his business because he was so focused on finding her. So I do believe that if he would have seen anything untoward, he probably would have investigated himself, if not, he would have called the police.
The Utah mountains are really rugged. My family owns a cabin in the mountains, it sits on the side of a mountain, with a lot of trees around it. In the area, there are 500 cabins, but it does feel secluded. Down below our cabin is a stream that is common use, can be used by anyone. We can hear the stream from the cabin, but when you go down to the stream, you can't see the cabin. And they might be 75 yards apart, at that. Anyway, I'm just babbling here so I'll quit.
Maybe if some reporter would go take a look and make pictures for publication of the hole and surrounding area, we could all understand what they're talking about. To me, a hole in the ground indicates a vertical hole (downward) like a well. A cave to me would not be a hole in the ground. If it were a cave, like in the side of a hill or cliff, I don't think you could cover it with dirt and the dirt "stay put". Sorry, but I'm hung up on "dirt-covered boards" and a hole in the ground. I know of two media outlets that have reported this (1) Fox (2) KSL-TV. Hey, I'm not trying to be argumentative, just trying to get a handle on what has been reported.