For everybody that has no idea what we are talking about, the US Army maintains a National Training Center at Fort Irwin, CA. It is wayyyy out in the middle of the Mojave Desert (not far south of Death Valley actually). It consists of nearly a thousand square miles of mountainous desert terrain interspersed with about a dozen or so towns and villages, some of which are amazingly large.
There is a local opposing force or OPFOR (the 11th Armored Cavalry Regiment) of about 5k soldiers, and they have vehicles that are mocked up to simulate Soviet style equipment (to include T-72s, BMP's, BRDM's, etc). Ten times a year, for almost a month, a Brigade rotates through for training (typically right before deploying downrange). It takes a few days to setup, then they have special training exercises for about a week, which are more scripted (including full up live fire events); followed by a week of "direct action" which is a free play unscripted maneuver battle between the OPFOR and the RTU (rotational unit). Its all scored using laser systems (MILES for those familiar), and the whole range is wired to track everything right down to each individual shot. There is air support including pretty much everything in the US inventory, and the battle literally encompasses the full spectrum, including electronic and cyber warfare.
Its a fascinating exercise, and has saved countless lives in Iraq and Afghanistan. The Army was lucky when it chose Fort Irwin in the 1980's, given that it literally looks exactly like Afghanistan, which has been helpful in putting on realistic exercises.