BillionGraves.com is the valuable world-wide cemetery mapping program that provides dynamic tools for analyzing the locations and clusters of graves. The basic program is free but the advanced features are only available with a subscription to the Plus version. If you understand what is available you will likely be persuaded of the utility of adding a subscription.
Note, I use the term "grave marker" to apply as the generic term applying to any physical evidence identifying a grave. This includes headstones, plaques, tombstones and any other type of marker.
The key feature of BillionGraves.com is the ability of the user to see geographic coordinate (GPS) information for all of the graves with photos of the grave markers. This system of user supplied photos is supplemented with "paper markers." If you are doing genealogical research, you probably realize that many graves, even in larger cemeteries, are unmarked. However, if the cemetery has records of the locations of the unmarked graves, as many do, or if you located an unmarked grave, you can use the BillionGraves program to "mark" the grave. All you do is create a paper copy of the grave marker and place in on the unmarked grave an upload the photo. The grave then appears in its correct geographically determined location with the paper marker as the reference point. In this way even cemeteries with no visible markers can be mapped by the program.
After photos of the graves have been uploaded to BillionGraves.com, volunteers can transcribe any information from the grave markers and enter in any other supporting information. Once the information is in the program, the location of a grave is marked on a satellite view map of the cemetery. Now the powerful analytic tools can be applied.
Here is a screen shot of Salt Lake City Cemetery in Salt Lake City, Utah. If you are familiar with this cemetery, it is the one in the Avenues on the hillside above downtown Salt Lake City.
There are 54,781 images in the BillionGraves.com file on this particular cemetery. The yellow dots represent the combined images of the graves in that area. If I zoom in, I can see the details of the graves.
Each of the yellow and green markers represent a grave in this area of the cemetery. Further zooming in reveals more about the individual graves. I you click on any marker, you can then see the information concerning the person in the grave. The map can be expanded to your full screen.
Of course, you can search for an individual grave. Here is a screenshot of the marker for my Grandfather Harold Morgan.
I can view the position of his grave on the map. Additionally, using the GPS function of my iPhone, I can drive and walk directly to the grave using the map which shows both my position and the position of the grave.
Now, I can see any nearby graves with an adjustable radius. This may take a few minutes depending on the size of the cemetery.
Now I can adjust the size of the search area and also search by first name, last name, birth year or death year. Here is the search for those with the Morgan surname. I can immediately see that I have family cluster.
The program also gives me the distance and direction of the additional graves from my original search. By expanding the circle, I pick up two more Morgans, possibly relatives or not.
The power of the program comes from its ability to identify the graves even when there is insufficient information on the marker. For example, if there is an infant buried with a grave marker that just says "Baby," its proximity to another grave may give a valuable clue as to the baby's mother or father. Likewise questions about whether or not a certain person is a family member or not may be answered by finding the family all buried in the same family plot.
I need to experiment with this further. I am planning on doing a webinar on this program in the next month at the BYU Family History Library Webinar Series. I should have a lot more information by then.