How Far can you Run in 12 hours?

I'm in!!! Just mailed off my check for the Timber Knoll 12 hour all-night run. The race is in three weeks time and coincides with full moon - it starts at 7pm and finishes at 7am the next morning. Another slightly different format - there is no set distance, it's however many 8.5 mile loops of Pedernales Falls State Park you can manage in the 12 hours. The course is all technical trail and I've heard a lot of good things about this series. I have a goal in mind but I'm keeping it to myself until after the race.