It took 30-40 dump truck loads of dirt. I rent a big farm house and the owner's son rides as well and we used his dump truck and tractor. We started building it a year ago, it takes lots of time. Before, the area you see was all trees...lots of chainsawin'! The dirt I used is somewhat sandy in appearance, only this stuff is more red and has some clay properties as well. We just dug it out of the pasture, so I don't know the scientific name of it or anything. As far as leveling them, we just stood back and looked at them and used a rake to manicure them. From time to time we get the rake out and spruce them up a little, but they hold there shape very well. The whoops have been through a year of hard riding on them with very little maintenence and are holding up great. Some of the landings for the doubles are dirt over old cars :lol
We are still continually working on it and hope to get a couple bobcats out there to get the track smoothed out and refined some more. We are adding another rhythm section and a bigger double on the back straight-away. Overall I'd say the track is only 2 acres or so.