I have never seen a graveyard at Fort Morris and I have been there numerous times. I have also been to the Sunbury cemetery and it is possible that the graves you are looking for are there. It is very close to Fort Morris and there are some very old graves there. I believe that a lot of the graves there have been lost over the years due to stones deteriorating etc. I do have a number of photos I have taken there...mostly Dunham graves since that is my wife's family name but I also shot pics of a lot of other older graves. Now that you mention it I have visited numerous forts in that area and have never seen a graveyard at any of them. I suppose bodies were shipped home to bury when possible.