(CNN)Mark Twain made this cave famous through his writings, and speculation swirled for decades that he’d signed his name somewhere inside it.
This week, the owners of the cave can finally confirm: “Sam Clemens,” Twain’s real name, is indeed inscribed inside the Mark Twain cave in Hannibal, Missouri.Clemens lived in Hannibal for most his childhood, from 1839 to 1853. Back then, the cave, first discovered in 1819 and containing three miles of passageways, was known as McDowell’s cave.It was a popular hang-out for locals, and over the years it has amassed nearly 250,000 signatures on its walls, according to Linda Coleberd, whose family has owned the cave since 1923.A look inside the Mark Twain cave from 2010.The cave figured prominently in Twain’s book, “The Adventures of Tom Sawyer,” published in 1876, and became famous thereafter.Read MoreFor decades, people have looked over the writing on the walls hoping to find Clemens’ own. In July, Coleberd and her friend, Cindy Lovell, finally discovered his signature.”My single hope has been that someone would find it during my lifetime,” Lovell said in a statement from the Mark Twain Cave Complex. “Sam knew the cave so well and described it in exact detail. We just knew it had to be in here somewhere.” Lovell, a former director of the Twain Museum in Hannibal, is a self-proclaimed “Twainiac,” and has been looking for his signature since 1996.The cave is rather dark, and Coleberd told CNN she was shining the flashlight around when Lovell spotted the signature not that far off the main passage way. Clemens was written in pencil about eye level on the cave wall. After analyzing a high resolution image, they also discovered “Sam” was written underneath.”He probably attempted to scratch his name and then used a pencil to write on top,” Kevin Mac Donnell, a Twain scholar and collector, told CNN.Mac Donnell, along with another Twain scholar, Alan Gribben, studied the signature and authenticated it.”First thing, you think it’s a prank, that someone wrote Clemens,” Mac Donnell said. “But when I saw it, I knew it was the real McCoy.”Mac Donnell and Gribben first compared the signature to those of Twain’s siblings and parents, to mark them off the list of potential Clemenses.”I am going to go on record as believing this to be Sam Clemens’s handwriting,” Gribben, a retired professor at Auburn University-Montgomery, said in the statement.”Moreover, his temperament was … far more egotistically assertive than those of either of his brothers, Orion and Henry, which makes it more likely that of the three he would be inclined to inscribe his signature on this site.”Mac Donnell studied the characteristics of how each letter was formed, the connecting strokelines and then compared it to an 1853 signature from Clemens, shortly after he left Hannibal.”I’m 99% certain of its authenticity,” Mac Donnell told CNN. “This is a pretty exciting discovery.”Colebred said they are now trying to figure out the right way to conserve the signature and be able to show it to the public on tours. Other famous signatures, like those of Jesse James and Norman Rockwell, have also been discovered in the cave.”Hannibal became a tourist destination 143 years ago when Twain published ‘Tom Sawyer,'” said Gail Bryant, director of tourism for Hannibal, in the statement. “This year, not only is Hannibal celebrating its bicentennial year, the Mark Twain Cave is also celebrating its 200th anniversary of discovery. We are thrilled that at long last Sam Clemens’s signature has been found in the cave that was named for him.”The cave is open year round for guided tours that last about an hour.”I’m jealous of the owners of the cave,”said Mac Donnell. “I have signed books, letters, photos, legal documents, checks, autograph albums, and even an opera fan, but no signed cave — not sure where I’d put it if I did have one.”