I've begun mapping sites that occur in Roughing It.  Chapter 1 was
simple, St. Louis and St. Joseph, Missouri.  Chapter 2 has Sam, brother
Orion and George Bemis on the Overland Stage heading west through
Kansas.  He reports stopping every ten miles or so.  These Overland
Stations and the Pony Express Stations I take to be the same.  I have
plotted ten such stations for Chapter 2.  The final station being
Cottonwood, where the Sphinx suggests they lay over for a few days.  The
National Park Service has a good on-line publication on the Pony Express
and there are any number of other on-line references.  But few of these
provide an exact definition of station locations.  My map can be seen at
http://bscottholmes.com/twain/roughingit/chapter2 . If anyone can
provide me with better coordinates I would be grateful.