"Overland with Mark Twain" (edited by Alan Gribben and Nick Karanovich)
is a publication of the Elmira College Center for Mark Twain Studies.
It's not very expensive, and I think there are still some copies
available.  Inquiries could be addressed to Lynne Rusinko
([log in to unmask]) or Gretchen Sharlow ([log in to unmask]).

Jim Leonard