During the past years I have participated in several activities to record gravemarkers at the City of Mesa Cemetery in Mesa, Arizona. In a recent effort, I helped my daughter and son-in-law with a very modest effort on my part, while they and their children photographed all of the gravemarkers in the entire cemetery for BillionGraves.com. But in the midst of that tremendous effort on the part of their family, I came to realize the numbers of people buried in that one cemetery who did not have the benefit of a gravemarker. This was brought home to me again in answering a query from FindAGrave.com to take a photograph of a gravemarker.
After a few minutes of research in the Cemetery's website, I found the cemetery record in the form of a PDF document of the gravesites with those without markers clearly indicated. This over 1100 page document contains thousands of names and has approximately 31 burials on every page. I could see that almost every page had a number of burials where the existence of a gravemarker was marked "no."
It is abundantly evident that websites such as FindAGrave.com and BillionGraves.com are extraordinarily useful to genealogists. But we should remember that not all of our ancestors had the opportunity to have their graves marked and that it is important to search the cemetery records recording internments, not just lists of gravemarkers. In this regard, I recently finished a project to scan the burial permits for the City of Mesa Cemetery. These records are now on the FamilySearch.org Historical Record Collection. I am certain that this type of record exists in many, many other cemeteries across our country and around the world. I would suggest that those interested in cemetery preservation concentrate on preserving, indexing and where possible, digitizing these records so that those graves without gravemarkers may also be preserved.