There's a new MX track open for business out in Bonney Lake. The track is pretty decent with lots of jumps. On the weekends they run 15 minute motos for dirtbikes and quads. On weekdays, you can reserve the track if you can get 8 or more riders together. The only drawback is that they seem to like to water the track right before the quads go out, so it can get pretty muddy. Here's a link for more info.......
link