High Quality Content by WIKIPEDIA articles! Mark Twain Riverboat is an attraction, located at the Disneyland theme park in Anaheim, California, on which passengers embark on a scenic, 12-minute journey around the Rivers of America. Originally named Mark Twain Steamboat when the park opened in 1955, the stately, 5/8-scale stern-wheeler was the first functional riverboat to be built in the United States for fifty years. Other Disney riverboat attractions now appear at Walt Disney World, Tokyo Disneyland and Disneyland Paris.