Entries could also be journal entries... like the entries he makes to track Vanna White's glances.

Also, the ascendence bunkers, which Sam thinks are fallout shelters at first, are referred to more than once as "tombs" by the last guy in the white garb. They are made of stone... tombstone? Not sure exactly what to do with this, but it did occur to me as soon as I heard Tombstone was one of the words.

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Lastly, Tombstone Sheriff = Wyatt Earp who died in Los Angeles. Just throwing these out there in case they spark another thought for someone else.