- "There it was. A simple, granite marker, smaller than most of the others around it, with three lines etched in the stone: / IN LOVING MEMORY / GEORGE DOUGLAS McFLY / April 1, 1938 - March 15, 1973 "
- —From Back to the Future Part II by Craig Shaw Gardner (quote, page 121)
Tombstones are markers for a particular grave to indicate who is buried beneath, and often their dates of birth and death, family relationships and notoriety.
In 1985A, Marty McFly found out that his father had been killed, and was buried at Hill Valley's Oak Park Cemetery. Upon going there, he discovered the tombstone, which was smaller than most of those surrounding it, confirming that George had indeed died in 1973. After Marty burned the Grays Sports Almanac in 1955, this nightmarish timeline was overwriiten by 1985B — which meant George was still alive in the future.
Later, on November 14, 1955, Marty and the younger Dr. Emmett Brown prepared to leave the Delgado Mine, only for Copernicus to be troubled by a grave at the nearby Boot Hill Cemetery. Both Marty and Doc looked at the tombstone to discover that it was the grave of the 1985 Emmett Brown, and took a photograph using Doc's camera.
After having arrived in 1885, Marty looked at the picture of the tombstone to keep track of his progress. Upon looking at the photograph after preventing Buford Tannen's shooting of Doc, it was revealed the name and date of death had been erased from the tombstone, but the marker's continued presence in the picture suggested that someone would be buried there — either EMMETT BROWN or CLINT EASTWOOD.
During his fight with Buford, Marty attacked him with the yet to be used tombstone, shattering it in the process. After winning, Marty took another glance at the photograph, just in time to see the image of the tombstone vanish before his eyes.