"David Paulides is a retired cop who found out through a conversation with a national park employee that there are a mulitude of unexplainable disappearances in U.S. national parks. The park employee explained how there seems to be a bit of a cover up, and this led David Paulides to compile a database on what he deemed high strange disappearances in National Parks all over the United States. I think many National Parks are placed on possible underground long time alien bases. This would serve those in the know by providing a convienent reason for why developers are not allowed to build or dig on these areas. Any now this. The disappearances coordinate with actual Deep Underground Military Bases in the US.