Yeah,next weekend(28th-29th).Google "offlimits tussock buster",they have a site with all the info.Looks well organised & fantastic country,all the desert country in the restricted army area.The free camping ground is the Waiouru rugby club ,which allows use of all their facilities (big screen & bar),plenty of time for beer & lies!
tussock buster was awesome, really nice flowing trails with expert sections and awesome hill climbs and all in picturesque scenery
bit dusty though, was cool to socialise at the end and have a few drinks then camp and do the same thing the next day