Mark Twain’s Signature Discovered in Cave Made Famous in ‘Tom Sawyer’ 

(AP) -- A pair of Mark Twain enthusiasts who have searched for more than two decades say they've found what appears to be Samuel Clemens' signature from his youth scrawled on the wall of the Missouri cave he made famous in "The Adventures of Tom Sawyer."

In the mid-1800s, long before he took on the pen name Mark Twain, Clemens and his young pals romped around the cave near the Mississippi River on the outskirts of Hannibal.