No idea where it is, but it looks like it's probably from a test firing range in an arid region somewhere

It's always been a shame to me that old artifacts are used for this purpose when any type of marker would serve the same purpose. Scores of F-86's were destroyed this way even up until more recent times. The CAF B-29 'FIFI' was found on a Navy aerial test range and just hadn't been hit yet. It had been stricken from all records because it was supposed to have already been destroyed.