The Eero Saarinen Gateway Arch, symbol of the opening of the west, dominates the Jefferson National Expansion Memorial on the Mississippi riverfront at St. Louis. The 630-foot stainless steel inverted catenary curve is the tallest monument in the United States. Trains of unique design travel through the legs of the arch to afford visitors night and day views of the city and the riverfront. The M. V. Huck Finn is headed downstream completing a sightseeing trip. Operates 4 trips daily. June 1st, to Labor Day.