If you are in the central Missouri area, you need to try the RC Barn near Jefferson City (midway between St. Louis and Kansas City)... BIG indoor offroad track -- great dirt racing action. Their website got hammered, and they are rebuilding it, but we have a forum on Heartland RC:
Outdoor tracks are making it hard to get good turnouts during the summer, but the track is in great shape, the owner really works to keep in that way, watering it all week so it's great for Saturday nights...
Right now it's only electric on Saturday nights, but in the winter, the Nitro guys show up and they have one day for Nitro and one for Electric, with racing every weekend.
Check it out!