I happen to rent my place from the Beytagh family. Their son Geritt is the 2008 Downhill Mountain Bike US National Champion. Geritt and his parents are my neighbor and they generously share all of their beautiful land with my kids and I. A few years ago Geritt and his friends built this pump track in their yard - here's some good footage of Geritt giving it a test run while Chewy motivates him.
My son, Riley, loves this pump track, but isn't quite ready to hit it with his bike. He still prefers to run it, which isn't an easy thing either. He must've done 20 laps on this track today asking to be timed for each one. Lotsa fun this afternoon!