Missouri River, S. Dakota to St. Louis
Hey Shannon, I've hesitated to jump in since I can only contribute to the very last bit of your journey. But here's a few of my St. Louis favorite places. We have some great Italian places...Trattoria Marcella on Watson (great food, you'll need a reservation), or Brazie's (I've never had a meal there that wasn't wonderful) on Hampton. Both in the $10 pasta, $17 entree range...great service, friendly and helpful. Or take a stroll down South Grand and check out Pho Grand or Mekong, both very reasonable Vietnamese (try the Shaking Beef at Pho.)
For a great Saturday go to Soulard Farmer's Market in the morning & get some fruit, (look for the farm stands, you can tell, the vendors look like farmers and they park their dusty pick-up trucks behind the stall)for local berries or peaches...go to the Hill (Little Italy) to Viviano's (a bonus, all the Viviano boys are very cute...) or DiGregorio's grocery for bread & meats...and then go have lunch at the little park across from the Humane Society on Macklind Avenue. Then go across the street & pet some doggies.
For dinner wash the doggie-spit off your hands and go to one of the places I mentioned earlier. Have a great time! I guess I should have asked if you'll have a car in St. Louis. Everything I mentioned is on the South Side and within the city limits proper. Not huge distances, but you would probably need a car.