Possibly the vault was rebuilt more than once. There’s some satellite or aerial images of the vault at http://www.realtor.com/realestateandhomes-search/Halfmoon_NY?disp=2#/lat-42.7356678716282/lng--73.724524083729/zl-19 Click “Road” and select “Bird’s Eye” and use the arrows to the right and left of the compass to rotate the angle of view. I don’t think Billy’s Way, the driveway into Hudson Preserve Luxury Residences, encroached on the cemetery. There’s trees on the east and south sides that probably indicate the historical boundaries. Chris