South Flank, Australia's largest iron ore mine in more than 50 years, achieved first production in May.
Once ramped up, it will produce 80 million tonnes of premium iron ore per annum, and together with the existing Mining Area C, will form the largest operating iron ore hub in the world, producing 145Mtpa of iron ore.
More than 100 Banjima traditional owners attended the event, which included traditional cooking, music, and dancing during a luncheon to celebrate indigenous culture.
Representatives from joint venture partners ITOCHU and Mitsui were also in attendance.
"South Flank is BHP's most technically advanced mine and creates the largest iron ore hub in the world," BHP Western Australia Iron Ore asset president Brandon Craig said.
"It will sustain more than 600 ongoing jobs, plus opportunities for hundreds of local businesses and billions of dollars in royalties to Western Australia."
South Flank's workforce is 40% women and 15% indigenous.
McGowan congratulated BHP on the milestone.
"It's investments like these that highlight our state's position as a secure and attractive place to invest," he said.
"Even during the height of the pandemic, this project still proceeded with construction and production because WA's resources sector was able to stay open and that has supported the local, state and national economy."
South Flank's high quality ore will increase WAIO's average iron ore grade from 61% to 62%, and the overall proportion of lump from 25% to 30-33%.
"South Flank's product has high lump content and increases the quality of BHP's blended products for steelmaking customers, improving blast furnace efficiency and supporting decarbonisation efforts," Craig said.
"South Flank's premium iron ore will be shipped to global steel producers to build electricity, transport and urban infrastructure around the world over the next 25 years."