Not sure about Missouri, but Nashville Superspeedway in Nashville, TN does trackdays. I think 2 or 3 a year. I did one there in August at night. Barbour Motorsports Park in Birmingham, AL is supposed to be sweet. Check www.sportbiketracktime.com
. They run trackdays across the country at different road courses. If you've never ran a trackday, the novice class is very informative. A very educational experience that not only teaches you racing techniques, but also makes you a better, safer and faster rider on the street. Good luck.
2000 Honda RC51 RVT1000R - Jardines, PCIII, K&N, -1/+2 sprockets, Speedohealer, 121.35 RWHP (my weapon of choice)
2000 Suzuki DRZ400S
1987 Honda CBR600F1 Hurricane - Yoshi pipe, K&N (stepson rides now)
1996 Kawasaki EX500 Ninja - Yoshi pipe, K&N pods, stage 3 jet kit PINK (wife's bike)
1985 Kawasaki ZN700A2 LTD - stock (cruiser/2up bike)