breeding area for brown and rainbow trout. The extra water boosted the amount of water available to the 10 other HEP stations on the Waikato River which flows from the north end of the lake and is its only exit. The productivity of pasture on the plateau was greatly improved in the 1950s once it was realised that the "bush sickness" suffered by local livestock was due to cobalt deficient volcanic soils. The diagnosis and cure for this was discovered by work of New Zealand scientists ( Grimmett and Shorland, senior chemists at the Department of Agriculture in 1934) who found that the iron ore which gave the best results contained significant amounts of cobalt, and went against popular wisdom by dosing animals with cobalt, with spectacular results. Australians Underwood and Filmer in 1936 confirmed this and solved a similar issue in cattle in Australia. However the application of cobalt at the rate of 30cc per Ha was only possible after World War II making use of war surplus planes and ex WW2 pilots for aerial topdressing. The cobalt was mixed with crushed phosphate rock which was obtained cheaply from Nauru Island in the West Pacific. The resulting mix was called Super Phosphate. The largest farm in the North Island including 13,800 hectares of land with about 9,500 hectares of developed farm land was established off the Taupō-Napier road and is called Lochinver Station. The station was largely developed by construction millionaire Bill Stephenson and his family using heavy earthmoving equipment in the 1960s and 1970s. In 2015 it was sold to Rimanui Farms after a bid by Chinese interests was blocked by the government. The high country sheep and cattle station has several airstrips, 21 houses and 200 km of roading. It historically carried 100,000 breeding ewes and about 8,000 cattle but now carries about a third of these. It has extensive shelter belts of contorta pine, improved rye-grass pasture and grows crops of swedes and barley. It previously was open to tourist and school group bus tours. Popular culture Tourism is an economic mainstay of the region with a wide range of largely outdoor attractions from trout fishing, flyfishing on Tongariro River or harling on Lake Taupō, tramping, Mountain biking centred on National Park, deer or pig hunting, horse riding to snowskiing/boarding on Mt Ruapehu. The Sir Edmund Hillary Outdoor Pursuits Centre of New Zealand is located on