Today was the highlight of my three weeks in Mount Isa so far. I was a guest of Nautilus Aviation to try out their new joy helicopter flights. The 20-30 minute flight would take me out to Lake Moondarra – Mount Isa’s water source and then over the town and the mine that dominates it.
The flight path follows the Leichhardt River, named for German explorer Ludwig Leichhardt. Leichhardt named many rivers as he crossed the Gulf of Carpentaria in his first south-north expedition in 1844-1845 from Sydney to Port Essington. According to explorer tradition he did not name any rivers after himself. However he missed this river which was later named in his honour. The river rises in the Selwyn Ranges south of Isa and meanders north emptying into the Gulf near Burketown.
About 15km north of Mount Isa is the manmade Lake Moondarra which dams the Leichhardt River. It provides water to the city and the mines. The lake is a beautiful spot with great birdwatching and is home to many water sports and fishing.
In 1956 the growing Mount Isa Mines was desperate for water to feed its growing copper and lead plants. They selected a dam site and started building but summer floods smashed the uncompleted wall. It was eventually completed in 1958 as was a 10km bitumen road from the city. It was the largest water scheme in Australia financed by private enterprise. On July 11, 1961 the dam officially became Lake Moondarra.
Lake Moondarra has a surface area of 23.75 km², a maximum depth of 11m and when full it can store 107,000 megalitres. It’s currently around 65% full after the cyclone that hit the Gulf late last year but has been under 20% full. It has also exceeded capacity on occasion with water spectacularly cascading over the spillway – which fortunately faces away from the city.
Mount Isa is Kalkadoon country. Kalkadoons lived across this rugged landscape of the Selwyn Ranges for thousands of years. They offered fierce resistance to white settlers until finally defeated by force of numbers and ammunition at Battle Mountain in 1884, The hills of their country are rich in minerals and the first white settlers noticed the telltale specks of green that denoted the presence of copper. Lead is also extensively mined as is silver and zinc.
The earliest mines in the region were at Cloncurry. But in 1923 John Campbell Miles stumbled across lodes of copper, silver and zinc on a trip to the Northern Territory. Miles named the area Mount Isa in honour of Mount Ida gold mine in WA. A town slowly grew around Mount Isa Mines (MIM) which started by mining lead, and later copper. In MIM’s heyday in the 1960s, it employed up to 5000 workers in its factories and pits which scarred the landscape. Low copper prices almost forced the closure of the copper mine last year but it has had a reprieve to 2022. MIM is now owned by embattled Anglo-Swiss multinational Glencore and it remains the town’s biggest employer.
The distinctive smoke stacks dominate Mount Isa’s skyline. The lead smelter stack stands 270m tall, built in the 1970s and used to be Australia’s largest manmade structure.
The city lies on the opposite side of the Leichhardt River to the mine. The population is now around 22,000 which although down on what it was in the 1960s-1970s, is still easily the biggest Queensland city west of Townsville and north of Toowoomba. Mount Isa is the commercial hub of north-west Queensland.
The Barkly Highway cuts through town from Cloncurry and goes north at the river junction to the mines. To the east it is 900km to Townsville via Flinders Highway, linking with the Landsborough Highway near Cloncurry which goes all the way to Brisbane. The state capital is some 2000km away, a two day drive or a two-and-a-half-hour expensive flight away. Mount Isa is nearer to Darwin than Brisbane, and probably has more in common with the tropical capital than the Queensland capital. North of Mount Isa the Barkly Highway links the city with the Northern Territory. On the right of the picture below is the city’s look-out towards the mines and also north (not pictured) to Buchanan Park, home of Australia’s largest rodeo, Mount Isa’s biggest event, which takes place every August.