I haven't actually ridden at Mill Creek, but my son has. It looked really good from my vantage point, and I look forward to riding it myself soon. Anyway, the boy says it's a good mix of fairly hard, and the sawdust filled clay. I know there is at least one really sandy (sawdust) section that runs behind the starting gate. Also, with practice and two motos, my son said his biggest problem was that he couldn't remember where he was on the track, or what came next. I hope this helps a little.