In 1969 Poseidon NL discovered nickel at Mt Windarra and quickly began the construction and development of an underground mining operation and processing plant. Western Mining Corporation (WMC) purchased the project and completed the development, with the first production of nickel concentrate in 1974. A total resource size of 8.5 million tonnes of ore @ 2.02% Ni for 172,000 tonnes of contained nickel metal was defined by WMC at Mt Windarra. The mine was advanced to a depth of 550m below surface and mining ceased in 1990 due to historically low nickel prices. By 1990 WMC had mined 5 million tonnes of ore at an average grade of 1.59% Ni producing 80,000 tonnes of nickel metal. By 1995 the processing plant was demolished and completely removed. The site was rehabilitated and the remnant headframe and remaining structures were turned into a tourist trail. In 2005 Niagara Mining began negotiations with WMC to acquire the project and by 2007 the infrastructure refurbishment was well underway, exploration drilling had begun and the company was renamed Poseidon Nickel Limited in honour of the original discoverers.
To date a JORC compliant resource at Mt Windarra of 4.77 million tonnes at a grade of 1.68% has been defined for a total of 80,200 tonnes of contained nickel metal.