The Pentagon intentionally muddied the waters. They never said it was at the altitude of 60,000 feet. They said it was 60,000 feet above sea level. You would have to look up how far the places were above sea level wherever it was at the time. I'm not sure why they reported it that way unless they just didn't want people to really know the actual "feet-above-ground-level" altitude.
Look at it this way - if they said it was 4,000 feet above sea level and it went near Pike's Peak it would mean it crashed into the mountain.
The Pentagon intentionally muddied the waters. They never said it was at the altitude of 60,000 feet. They said it was 60,000 feet above sea level. You would have to look up how far the places were above sea level wherever it was at the time. I'm not sure why they reported it that way unless they just didn't want people to really know the actual "feet-above-ground-level" altitude.
Look at it this way - if they said it was 4,000 feet above sea level and it went near Pike's Peak it would mean it crashed into the mountain.
Altitude is measured in a few different ways and can be confusing.
https://hartzellprop.com/altitude-measured-aviation/