I am having a difficult time dealing with reports of Mark Twain in
Muskegon.  References to it seem to be all linked back to a letter sent
to Andrew Chatto.  Caldwell had it dated as December 4, 1884.  It is
listed in the Mark Twain project as December 14, 1884.  A December 4
date would be absurd.  Caldwell has Twain and Cable travel from Ithaca,
NY to Muskegon, then back again to Rochester, New York.  Any tour
manager that would set a schedule like that would be immediately fired.
I suspect he made of notation error in his notes while researching his
book and he merely perpetuated this error, and expanded it, while
writing his book.

Fears has the date corrected to December 14, the date reported in The
Mark Twain Projects list of letters, a Sunday, and reports that they
gave a reading in Muskegon on this date.  This is also very unlikely as
it would have required Cable to both travel on a train and "work" on a
Sunday.  

There was no train route from Grand Rapids to Muskegon (at least none
built by 1870, which is the extent of railroad routes I have
available).  There is a route that terminates close to Muskegon,
however, at Grand Haven.  This is a 23.6 km line.  

So, why would Sam travel to Muskegon, on a Sunday, just to post a short
letter to his publisher in England?  It appears that Muskegon does feel
some affinity to Mark Twain, though.  Their Chamber of Commerce
recently sponsored a multimedia event, "When Mark Twain Came To
Michigan: Multi-media presentation with Al and David Eicher".  

Most references I find for Twain in Michigan deal with his 1895 run
through the state on his way to the Pacific Ocean. Twainquotes.com has
no mention of a December 14, 1884 speaking engagement.