I hung around Corey & Malinda's apartment most of the day. I washed my tent, applied waterproofer, and let it dry thoroughly, tightened the shock cords in the poles, and sanitized my hydration pack.
In the afternoon Malinda picked me up and we rode out to Cahokia Mounds in Illinois, though by the time we got there we didn't have much time to see the museum before closing. We climbed Monks Mound (the largest prehistoric structure in North America) and walked over to Woodhenge.
After a pizza dinner, we went back into downtown St. Louis to visit the City Museum, but it was closed -- during the summer it's open evenings, but in the fall it's only open weekend evenings. It looks fascinating, so I'll just have to come back!