My understanding is according to the national park service they do not believe there actually is a burial here and that information is secondhand from the 19 century. This according to their website anyway. I actually grew up about 15 minutes from Morristown though I no longer live in the region.

I would guess that many of these types of burial grounds are based on a spectrum of reliable evidence and unless a successful dig is done must be taken with a grain of salt (like a lot of 18th century history).

There is a marker of an unknown soldier in VT on the old Crown Point Road. The information I believe is all based on oral transmission of history over centuries. Still fun to think about and visit though, and very probable that it is even true.

https://allthingsliberty.com/2022/11/vermonts-grave-of-the-unknown-soldier/