At its peak, Koolan Island had a golf course with a par-7 hole that doubled as the airstrip. At 790 metres (about 864 yards), it was the world's then-longest golf course hole — which tells you something about how mining companies build towns on remote islands, and something else about what happens when an ore body runs out and the people leave. When BHP finished at Koolan Island in 1994, they had extracted 68 million tonnes of high-grade haematite ore. Then they pumped seven million cubic metres of seawater into the pit, let a marine ecosystem establish itself in the void, and handed the island back to time.
Koolan Island sits in the Buccaneer Archipelago off the Kimberley coast of Western Australia, about 1,900 kilometres north of Perth and 130 kilometres north of Derby. The island is composed of Paleoproterozoic rock 1,600 to 1,800 million years old — hematitic sandstone and conglomerate with haematite ore averaging 67 percent iron. BHP's subsidiary Australian Iron and Steel began open-pit mining here in 1951, simultaneously with the neighbouring Cockatoo Island operation, shipping ore on company-owned vessels to Port Kembla.
At its peak, the island supported a population of 950 people. It had a school, a police station, shops, recreation facilities, and that remarkable airstrip-golf course combination. The community was entirely dependent on the mine, connected to the mainland by company logistics. When the ore body was exhausted, the town ceased to exist. Buildings were removed, exotic vegetation cleared, and native species replanted across the island in an extensive rehabilitation programme.
By the time BHP finished in 1994, the base of the main pit was 80 metres below sea level. Rather than dewater and seal the pit, the company made an unusual decision: they excavated a channel from the ocean, allowing the sea to fill the void. Seven million cubic metres of seawater entered what had been a mine. A productive photic zone marine ecosystem developed within the bounds of the former pit — coral, fish, and invertebrates colonising the engineered underwater space.
In 2007, Mount Gibson Iron re-commenced mining at Koolan Island. A seawall was completed in 2011 on the ocean side of the main pit, allowing it to be dewatered for another round of extraction. In April 2006, the company signed a co-existence agreement with the Dambimangari — the traditional owners of the island, who are Dambima/Worrorra-Ngardi people — aiming to ensure that 30 percent of the 220-person workforce would be filled by Indigenous employees.
In 2014, the seawall failed. The pit flooded. The rebuilt seawall and the years of work to re-establish the mining operation had to begin again. By August 2018, dewatering was underway once more. Shipments of iron ore to China recommenced in April 2019.
In October 2025, Mount Gibson Iron announced the mine had closed permanently after a rockfall made operations unsafe. With closure already scheduled for September 2026, the company deemed it uneconomic to reopen. The 450 redundancies that followed were the final chapter of more than seventy years of continuous industrial history on an island 1,900 kilometres from Perth.
Koolan Island had also witnessed a smaller tragedy on 23 December 1984, when a Cessna 210 that had just taken off for Broome struck power lines near the end of the gravel strip and somersaulted. Six people were killed. The strip, affected by a recent cyclone, was in poor condition. The aircraft may have been overloaded. Six people died on Christmas Eve's eve, at the edge of one of the most remote mining operations on earth.
Koolan Island is at 16.13°S, 123.74°E in the Buccaneer Archipelago. The island's airstrip runs east-west; check current status before landing as operations changed with the 2025 mine closure. The Yampi Sound Training Area lies to the east — obtain NOTAMs before any low-level flying in this area. At 2,000–4,000 feet, the main pit and engineered seawall are visible from the air. Derby (YDBY) is the nearest major aerodrome, approximately 130 km south.