When people think about Hannibal, Mo., author Mark Twain might be the first thing that comes to mind.Twain, aka Samuel Clemens, grew up in the small town on the Mississippi River. His life there, and on the steamboats passing through, inspired his writings for “The Adventures of Tom Sawyer” and “The Adventures of Huckleberry Finn.”Another well-known resident was Molly (Tobin) Brown, who survived the sinking of the Titanic and whose life became a Broadway play and then Hollywood movie, “The Unsinkable Molly Brown.”In 1967, three more residents became internationally known, brothers Billy Hoag, 11, and Joel Hoag, 13, along with their friend Craig Dwell, 14. People from all over the world came to Hannibal for what would become one of the biggest search parties in American history.In Hannibal, the boys’ disappearance is still talked about.“There’s a remarkable amount of history in Hannibal; it’s had a big impact on the state and a lot of colorful and famous people lived here,” said Lisa Marks, historian and co-founder of the Hannibal History Museum.Still, “When I moved here 10 years ago (the story of the lost boys) was one of the first things I learned about the town’s history,” she said.The story was interesting enough that out-of-towner John Wingate, of Minnesota, published “The Lost Boys of Hannibal: Inside America’s Largest Cave Search,” at the end of last year.Marks will be at the Warren County History Museum at 6 p.m. Tuesday, Oct. 2, to talk about the event based on evidence from Wingate’s book and her own research.Marks will bring the audience back to late 1960s Hannibal and set the scene; a region of caves, some underground and connected to waterways, a modern highway under construction and a time when little boys regularly went on unsupervised adventures.The boys left together and didn’t come home. Their disappearance prompted a massive search that attracted help from all over the world.“Local officials didn’t have the means to do a search the way we would do today,” Marks said. “But experienced cave explorers came to search. People from all over descended Hannibal.”The town was too small for its temporary residents. It didn’t have the infrastructure for all the volunteers, many of whom were risking their own lives in search of the lost boys. The dark, watery underground caves were the most dangerous places to go.Marks said the community learned that no matter how skilled rescuers are, their lives must also be protected.“Since that tragedy, if there’s a rock slide on one of cliffs that creates an opening, they are immediately sealed,” Marks said.Many people who were in Hannibal in 1967 are still there.“It’s an unsolved mystery and people are still talking about what could have happened,” Marks said. “Hannibal is a small town. For an event to grow as large as it did, with thousands involved in the search, it shook the community. But it also brought the community together.”The event will be held at the Warren County History Museum, 202 W. Walton, Warrenton. Marks will have photos and displays with her presentation. Copies of “The Lost Boys of Hannibal: Inside America’s Largest Cave Search” will be available for purchase.The Scenic Regional Library Warrenton Branch is hosting the event. RSVP by calling 636-944-6100 or online at scenicregional.org.Warren County Historical Society Museum