Great fall fun on MTB or Cyclocross bike.. AND KIDS RACES
The Dirt Derby is held on Tuesdays in the fall at theAustin/Del Valle Motorcross Park (http://www.advmxpark.com/)(ADVMX), just around the corner from Austin-Bergstrom International Airport at 14600 Pearce Ln, Del Valle. It is one mile east of SH-130 and only 20 minutes from downtown Austin.
Click on Link for more.. This is a race series.. Small cost per race.