Before you go, buy 1 Standard Hut Ticket (blue for adults, yellow for youth) for each night's stay. Put this in the honesty box at the hut. Or buy a Backcountry Hut Pass that gives unlimited use at most Standard and Serviced huts for a 6 or 12 month period.
NZTopo50 map sheet: BT27
Grid/NZTM2000 coordinates: E1653381, N5319428