Update:
Last week, I received an email from one of the property owners for the motel. See the attached photo of the cache. It is actually in much better shape than I expected. But I wonder what the contents look like after being exposed to all that heat? Regardless, I may never find out. The property owner told me that the building is very unstable in this area. I asked him about maybe retrieving it when they tear down the walls and start removing the debris, before it is carried away in a dump truck. But he has not responded and I suspect I will not be allowed to get it. I drove by the site a few days ago and it is all fenced off with No Trespassing signs posted, and no indication of any work being done beyond that.
"There are not enough Indians in the world to defeat the Seventh Cavalry." -- George Armstrong Custer