Underground mining in Australia

Most of Australia's metal comes out of open pits, but many of its richest and deepest orebodies are mined underground: copper at Olympic Dam, gold and copper at Cadia, tin at Renison Bell. Here is how an underground mine works, step by step, and where they are.

Short answer

Underground mining reaches ore too deep to dig out from the surface. In Australia most metal mines go down by a decline, a spiral ramp trucks drive down, and mine the ore in large blasted blocks called stopes, filling them with paste afterwards. The biggest, lowest-grade orebodies, such as Cadia and Northparkes in New South Wales, are block caved. The largest underground mine is BHP's Olympic Dam in South Australia.

Declinethe spiral ramp most Australian metal mines are entered by

Stopinghow most ore is mined: big blasted blocks, backfilled afterwards

Block cavingfor giant low-grade orebodies: Cadia and Northparkes

Olympic DamAustralia's largest underground mine

How an underground mine works

Press Play, or pick a part, to see how ore is reached and mined below the surface.

Schematic, not to scale. Depths and methods vary from mine to mine.

Map of underground mines in Australia

The major underground mines, from the copper of South Australia to the tin of Tasmania. Mines marked lime are on our globe with their company's project page.

On our globe (company project page)Other major underground mines

Hover or tap a mine; tap again to see its row in the table. State outlines: Natural Earth.

Mine	State	Operator	Mines	Method
Olympic Dam	South Australia	BHP	Copper, uranium, gold, silver	Sublevel open stoping
Cadia	New South Wales	Newmont	Gold, copper	Block caving
Northparkes 3D	New South Wales	Evolution Mining	Copper, gold	Block caving
Ernest Henry 3D	Queensland	Evolution Mining	Copper, gold	Sublevel caving
Renison Bell 3D	Tasmania	Metals X	Tin	Sublevel open stoping
Mungari (Frogs Leg, White Foil) 3D	Western Australia	Evolution Mining	Gold	Open stoping
Cowal 3D	New South Wales	Evolution Mining	Gold	Open stoping (from 2024)
Telfer 3D	Western Australia	Greatland Resources	Gold, copper	Sublevel caving and open stoping
Kanmantoo 3D	South Australia	Kantra Copper	Copper, gold	Open stoping
Mount Isa copper	Queensland	Glencore	Copper	Sublevel open stoping (closed 2025)

Underground mining methods used in Australia

Sublevel open stoping

The workhorse of Australian metal mines. Levels are driven above and below a block of ore, rings of long holes are drilled between them and blasted, and the broken ore is pulled out of the bottom by remote-controlled loaders. The empty stope is then filled with cemented paste made from the mine's own tailings.

Block and sublevel caving

For huge orebodies of modest grade. Instead of blasting every tonne, the rock is undercut so it caves under its own weight and is drawn from below. It is the cheapest underground method per tonne, but the surface above eventually subsides. Cadia, Northparkes and Ernest Henry use caving.

Cut and fill

For narrow, high-grade veins, common in gold. Ore is mined in horizontal slices from the bottom up, each slice filled before the next is taken, so miners work off the fill.

Longwall (coal)

Most underground coal in the Bowen Basin and the Hunter is mined by longwall: a shearer runs along a coal face hundreds of metres wide under moving steel roof supports, and the roof collapses behind it.

Underground or open pit?

An open pit digs out everything above the ore, so it suits big, shallow orebodies: the Kalgoorlie Super Pit, the Pilbara iron ore mines, Greenbushes lithium. As a pit deepens, the waste moved for each tonne of ore (the strip ratio) climbs, until tunnelling to the ore becomes cheaper. That is why so many Australian mines, Ernest Henry, Kanmantoo, Cowal and Cadia among them, have gone underground beneath their pits.

Satellite view of the Olympic Dam surface plant in South Australia — Olympic Dam from above: the smelter, refinery and shafts are all you see of a mine that lies hundreds of metres down. Satellite imagery: Powered by Esri · Esri, Vantor, Earthstar Geographics, streamed live; image dates vary.

Underground mining in Australia today

Australian underground mines are among the most automated in the world: loaders and drill rigs run by remote control from the surface, autonomous trucks on declines, and battery-electric machines that cut diesel fumes underground. The trend is deeper and bigger, with block caves replacing many stoping mines in copper and gold. For what Australia mines, and the projects listed companies are drilling, see mining in Australia, its states such as Western Australia, and the WA drilling map. How underground drill results are read is in how to read drill results.

Questions

What is underground mining?

Mining through tunnels and shafts to reach ore that is too deep, or too narrow, to dig out economically from an open pit. Only the ore and the tunnels to it are dug, so far less waste rock is moved than in a pit.

What are the main underground mining methods in Australia?

For metal mines, sublevel open stoping (with paste backfill) is the most common, then sublevel caving and block caving for large low-grade orebodies. Coal mines in New South Wales and Queensland mostly use longwall mining.

What is the largest underground mine in Australia?

Olympic Dam in South Australia, run by BHP, mining copper, uranium, gold and silver from hundreds of kilometres of tunnels.

How deep do Australian underground mines go?

Many are 1 to 2 km deep. Mines get deeper over time as the upper ore is used up, which brings heat, rock stress and ventilation challenges.

Is underground mining safer than open pit mining?

Both are run under state mine-safety laws with strict controls. Underground mines have extra hazards, such as rock falls, ventilation and fire, which is why modern mines use remote-controlled loaders, ground support and refuge chambers.

Why do mines go underground after an open pit?

As a pit deepens, more and more waste rock has to be removed for each tonne of ore. At some depth it becomes cheaper to tunnel to the ore below the pit, as at Ernest Henry, Kanmantoo and Cadia.

Sources

Checked against the sources above on 24 October 2026.

Figures are as each source publishes them. Company output is shown as the mines report it; nothing here rates a company. Not investment advice.