The old western television show "The Rifleman" had an episode with Twain
traveling to North Fork, New Mexico.  Here's the imdb.com entry:
http://www.imdb.com/title/tt0686729/  In this episode, Mark, Lucas McCain's
boy, is awestruck by the arrival of his literary hero, but Twain ends up
being a jerk to him, though it's discovered later that Twain is secretly
mourning the recent death of his son.

In fact, here's the imdb.com listing for Mark Twain as a character:

http://www.imdb.com/character/ch0033269/


Mike