Situated just off Highway One, 50 kilometres north west of Whyalla, Iron Knob is the birthplace of the Australian steel industry.

Iron ore was first discovered here in the mid Eighteenth Century, but it was not until 1899 when BHP (BHP Billiton/BHP Steel) was granted iron ore leases that the true value of the rich high grade ore deposits were recognised. The mine operated for 99 years with 150 million tons being mined from the twin leases of Iron Knob and Iron Monarch.

Today Onesteel Whyalla Steelworks primarily operates from Iron Duke in the Middle Back Ranges.