Who's Buried In Rowe's Tomb?

Yesterday, R and I made the last-of-the-season woods walk.  Too many nasty, illness-bearing ticks are becoming active.  Our last walk was to locate Major John Rowe's tomb.  Major John Rowe was a Revolutionary War veteran and some of our local maps...Forest Fire Department and the Eben'r Pool map are just two...mark the location of Major John Rowe's tomb.

My red mark shows the designation "Major John Rowe's tomb"

So we set out on our quest at the top of Rowe Avenue.  Our last visit to this area did not yield the discovery of the tomb.  Last time we found the remnants of a large quarry building and that was fun to explore and photograph.

Old stone building

A shot from inside the building

This time we found the tomb.  Or, at least, something very tomb-like in the area designated as THE tomb on the maps.

Tomb-like structure built into the hillside

The tomb has been opened.  And graffiti-ed inside.

Large, rectangular vault built from quarried stones and cement

Now, there is a problem with this entire tomb thing.  I did a bit of research about Major John Rowe and that research confirms the information on file at Find-A-Grave.

Birth:    Aug. 8, 1737

Rockport

Essex County

Massachusetts, USA

Death:   Jun. 14, 1801

Ballston Spa

Saratoga County

New York, USA

Revolutionary War veteran. Commanded a company of militia at the Battle of Bunker Hill.

Note: Memorial stone (in Union Cemetery, Rockport). Major Rowe is buried in Briggs Cemetery, Ballston Township, New York.

Indeed.  So, if the Major is buried in New York and there is a memorial plaque at Union Cemetery in Rockport...what's up with Major John Rowe's tomb?

Who was buried in Rowe's tomb?