Was There Ever a Stone?

If you think, based on family tradition, an obituary, a death certificate, etc. that a person is buried in a certain cemetery, keep in mind that there might not be a stone for them. Some families, for whatever reason do not erect a stone after the burial. It can be difficult to find what was never there. 

It is always possible that the marker was a wooden one that did not pass the test of time. 
And some stones fall down and are buried themselves.