Cache is not at posted coordinates in river. Figure out where it is.
The River Road bridge at Safe Harbor has been closed for a few months. While discussing its recent re-opening, I noticed this quote in a post on Facebook. Did Mark Twain really say that? I learned there is a web page at the Center for Mark Twain Studies for debunking quotes attributed to Mark Twain - The Apocryphal Twain. They have a thorough analysis of several quotes he did not make. Interesting reading.
Your task is to find the coordinates in this puzzle ....
When you have coordinates, realize that Twain did make several comments about death including about his arriving and departing with Halley's Comet. Twain did not write, "Alas, poor Yorick!" That's relevant to the hide.