Mount Clayton was a mountain in which Boot Hill Cemetery was built into. Its elevation was 2761 feet above sea level. While trapped in 1885, Emmett Brown hid the DeLorean time machine inside a mine within the mountain. He subsequently drew a 1:164 scale map of the mountain, the mine and the cemetery to allow Marty McFly and his younger 1955 self to find the time machine.
Behind the scenes
The map detailing Mount Clayton and surrounding schematics noted a board carved with the name "Marty" in it. In Back to the Future Part III, the board instead reads "E.L.B." for Emmett L. Brown.
- Back to the Future Part III (At cemetery and on map)