National Park Lake Frome Regional Reserve Lake Gairdner National Park Lake Gilles Conservation Park Lake Torrens National Park Mount Brown Conservation Park Mount Willoughby Indigenous Protected Area Munyaroo Conservation Park Mutawintji National Park Nantawarrina Indigenous Protected Area Pandappa Conservation Park Pinkawillinie Conservation Park Pualco Range Conservation Park Simpson Desert Regional Reserve Strzelecki Regional Reserve Sturt National Park The Dutchmans Stern Conservation Park Vulkathunha-Gammon Ranges National Park Wabma Kadarbu Mound Springs Conservation Park Whyalla Conservation Park Winninowie Conservation Park Witchelina Nature Reserve Witjira National Park Yalpara Conservation Park Yellabinna Regional Reserve Yellabinna Wilderness Protection Area Yumbarra Conservation Park Mining Other than agriculture and tourism, the primary economic activity in the vast and sparsely settled desert is mining. Owing to the almost complete absence of mountain building and glaciation since the Permian (in many areas since the Cambrian) ages, the outback is extremely rich in iron, aluminum, manganese and uranium ores, and also contains major deposits of gold, nickel, copper, lead and zinc ores. Because of its size, the value of grazing and mining is considerable. Major mines and mining areas in the Outback include opals at Coober Pedy, Lightning Ridge and White Cliffs, metals at Broken Hill, Tennant Creek, Olympic Dam and the remote Challenger Mine. Oil and gas are extracted in the Cooper Basin around Moomba. The Tanami Desert features The Granites gold mine and Coyote Gold Mine. In Western Australia the Argyle diamond mine in the Kimberley is the world's biggest producer of natural diamonds and contributes approximately one-third of the world's natural supply. The Pilbara region's economy is dominated by mining and petroleum industries. Most of Australia's iron ore is also mined in the Pilbara and it also has one of the world's major manganese mines. Transport The outback is reticulated by historic tracks with excellent bitumen surface and well-maintained dirt roads. The Stuart Highway runs from north to south through the centre of the continent, roughly paralleled by the Adelaide–Darwin railway. There is a proposal to develop some of the roads running from the south-west to the north-east to create an all-weather road named the Outback Highway, crossing the continent diagonally from Laverton, Western Australia (north of Kalgoorlie), through the Northern Territory to Winton, in Queensland. Air transport is relied on for mail delivery in some areas, owing to sparse settlement and wet-season road closures. Most outback mines have an airstrip and many have a fly-in fly-out