 In 1962, Dr Ian Reilly from the now defunct Department of Scientific and Industrial Research calculated the geographic centre of New Zealand (including Stewart Island and some smaller islands in addition to the North and South Island, but excluding the Chathams) to be in a forest in Spooners Range southwest of Nelson at .Owing to the coarse nature of the underlying data (use of rectangular areas of 7.5 minutes of arc on each side), the centre calculated by Dr Reilly has quite large error margins.Recalculating the result with more modern and accurate data shows the geographic centre of New Zealand is approximately 60 km southwest of Nelson, in the Big Bush Conservation Area north of Saint Arnaud, New Zealand.