Likely rule against Mark.
Mark and Charles had an oral agreement over a few years and nothing was put into writing. This would trigger the statute of frauds, wherein certain types of agreements are required to be memorialized in writing.
This means that there is a situation in which two people are having to be taken at their word. On top of that, the agreement was made while they were impaired.
If a court didn't rule against Mark at the outset, there would be an investigation into whether the agreement was enforceable, how impaired they were, whether anyone else heard them, and what the historic uses were but there isn't enough time for a prescriptive easement or adverse possession. But this is likely a summary judgment case based on statute of frauds.