Mummy at Chauchilla cemetery

Here is another closer look of one of the many mummies exposed in the cemeteries. There were many of them on this site. Most of them were really well preserved despite the exposure to the element of nature. We were told that these mummies were the really thing, not replicas. I don't know if it is true or not.  How long can the mummies be preserved in their mint condition when there is no cover to protect them?  This is almost as neglected as the treasures and artifacts in Egypt where they have so many that they ran out of spaces and money to deal with them.