Todd, a good way to leave messages at a grave site is put the message in a glass canning jar and put the lid on tight, and bury it part way in the ground. Be sure to use a pen that the ink will not fade. Be sure to let the caretaker of the cemetery know so he will be careful when mowing. There is a grave marked by this way not far from where we live here in Oklahoma. It has been ther for years. Ellen