This stretch of scenic Highway 100 is best experienced from the back of a motorcycle, but you can approximate the effect by calling shotgun and riding with your window down. Reflecting blue sky on a sunny day, the muddy Mississippi becomes a glittering ribbon, dotted with boats (sailboats even!). You'll wonder whether this is the same river that carries debris past the Gateway Arch downtown. It might be nice to take in the water from the deck of a restaurant, but you'll find it's more fun to just drive. Before you know it, you've covered five miles and you're upon Grafton, where tourists licking ice-cream cones wander across the road like unfenced cattle. Stop here for a treat and inspect a few knickknacks. When you've inhaled enough dust from the passing parade of Harleys, it's time to hop in the car and head south again. This time the limestone bluffs are on the driver's side, and the view is all yours.