My neighbor had this built to deal his land. When the pines were planted, the land was cut into these valleys and ridges about a foot tall. If you drive with them, they are nice and smooth, but driving over them is a nightmare.
He used C Channel and drags it behind his tractor. First few passes were very hard because of the constant bouncing, but it quickly smoothed things out.
After I took this picture, he said he added some more steal to it to make it more aggressive and now it works even better.
The advantage to this over the log and fence method is this thing cuts high spots and fills slow spots really well.
After seeing this, I hooked a chain onto my pallet forks and draged them around on their sides. They are almost too heavey for my 35 hp tractor, but do a better job of cutting down the high spots than the log does.
Eddie