Highland Homeowner's Association

I am unclear on the regulations for using private property in this area. I previously thought that to grant permission to use the private property, in this case, the neighborhood quarry, one could be given permission by an owner of the property and could use the land. Recently, however, I was told by someone that anyone under 21 must have an escort who is 21 or older. I am fairly certain that this is not true but I wanted to clarify this before I violate any rules or regulations.