 Although this park was abandoned in favor of the much larger Disneyland, the plan for having a riverboat attraction was retained.Because "Mark Twain" was the first functional paddlewheeler built in the United States in fifty years, the WED designers conducted extensive research to build it like riverboats were built in the heyday of steam powered ships.The decks were assembled at the Disney Studios at Burbank, while the 105-foot hull was constructed at Todd Shipyards, Los Angeles Division, San Pedro, California (where portions of "Columbia" were built years later).