Mark Twain Cave and Tom Sawyer’s Cave

What Is Actually True

• The operator says the cave was found in 1819 or 1820 by Jack Simms and carried earlier names including Saltpeter Cave and McDowell’s Cave before taking the Mark Twain name in 1880.
• It says Dr. Joseph Nash McDowell bought it in 1848 and used it for experiments on dead bodies, and that young Sam Clemens visited, which the operator says inspired a graveyard scene in Tom Sawyer.
• The operator says the entrance used today was blasted out in 1890.
• In July 2019 two visitors found a pencil signature reading “Clemens”; the operator says scholars concluded it was likely Sam Clemens’s, written several years before he left Hannibal in 1853.
• The treasure room and Injun Joe are fiction; the operator lists them as story features tied to spots in the cave.
• The history here is the commercial operator’s account; we did not read a state or National Park Service page on it.