How would you build this?

Looking to do the same thing, with 70 acres of flat iowa farmground. The site pictured is only 15, but I would extend the rifle range pictured from 100 yards to 1000. Same amount of smaller pistol bays though. Lay it all with a scraper and build a nice sized pond out of the borrow pit? Or push it all up with a dozer feathered across the whole property? Or push piles to an excavator? Other ideas?