Iron Knob is located 52kms north-west of Whyalla adjacent to the Eyre Highway and is know as the birthplace of the steel industry. BHP was granted iron ore leases in November 1899.  Ore was initially used at Port Pirie as a flux during the smelting of silver, lead & zinc ore. After 100 years mining at Iron Knob ended when the last ore was taken from Iron Monarch open cut pit in April 1998. It was re-opened in 2012 & ore was once again transported to Whyalla.

Iron Knob stunning piece of landscape in the Middleback Ranges between the Lincoln and Eyre Highway.  Rail line transports all the ore through to Whyalla Steelworks now owned by Onesteel. The Whyalla Steelworks and Mines were spun-off/separated from BHP company in October 2000.