Lake Pinaroo, Sturt National Park. Was This Sturt’s Inland Sea?

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Charles Sturt had an idea. He was convinced an inland sea covered much of inland Australia.

To Sturt, everything pointed to it. The rivers flowing west from the Great Dividing Ranges and even the regular sightings of waterbirds flying North-West between Melbourne and Adelaide.

The beginning of the long walk across the lake bed. Lake Pinaroo, Sturt National Park NSW.
Maybe Sturt would have declared he had discovered his inland see if he’d seen Lake Pinaroo full!

So in 1845 he set out from Adelaide to find this mythical inland sea. He followed the Murray then the Darling, finally striking out North-West into unknown country.

And that’s how he ended up in the Corner Country in New South Wales… complete with a boat and sailors!

Getting There

Fort Grey Campground in Sturt National Park is a bit easier to get to these days. It’s just off the road along the Tibooburra – Cameron Corner Road. The campground is about 100km from Tibooburra and 30km from Cameron Corner, and just off the road.

Remember though, it’s still remote country and you have to be entirely self-sufficient.

Once you arrive at the campground, National Parks have spoilt you. Two lots of gas BBQs under shelters and two separate toilet blocks make camping a bit easier. And there’s plenty of room to set up and have some space.

The facilities at Fort Grey Campground are excellent. Lake Pinaroo, Sturt National Park NSW.
The facilities at Fort Grey campground are excellent. Sturt National Park.

Like many National Park campgrounds, fires are not permitted. There’s a couple of reasons. One because this is arid zone country with cold nights and often warm, windy days. It’s easy for a campfire to spring back to life mid-morning, once the air heats up and the wind starts.

The second reason is that all dead timber is precious in this country. It’s a critical part of the dune country life cycle. Termites eat eat timber, small reptiles eat termites, tiny marsupials eat insects and small reptiles, kites and eagles eat the marsupials and so on.

Plus the fallen timber plays a vital role in holding the fragile sands together and providing ground cover.

And as you drive in, you can’t help but notice a giant quoll at the entrance. This is one of three magnificent wire sculptures on the drive between here and Cameron Corner.

Lake Pinaroo Walk

When you stay at Fort Grey Campground, the Lake Pinaroo walk is a must-do walk. It starts at the eastern end of the campground and does a clockwise loop past the Old Fort Grey homestead, across the lake past an Aboriginal cooking hearth, onto an old well, past the remains of a timber brush fence then back over sand dunes to the campground.

Just after the well, you can also strike out across the lake to Sturt’s campsite. This is a one way route.

Our take on the Lake Pinaroo Walk, Sturt National Park.

NSW National Parks have done a remarkable job installing interpretive signage in many spots along the walk. We always enjoy these signs because it brings the place to life.

Let’s have look at the highlights of this walk in more detail.

Lake Pinaroo

This ephemeral lake rarely fills. The huge rains of 1956 and 1974 were the standout flood events which had water lapping near the top of the dunes. And when you look at where the water has to come from, then you begin to understand why a filling event is so rare.

1974 high water mark. Lake Pinaroo, Sturt National Park NSW.
The 1974 flood high water mark. Back in the trees behind Peta you can just make out the white shoreline of Lake Pinaroo. That’s a lot of water!

The Lake was listed as a Ramsar site of significance in 1996. For more information, go here.

If you drive out from Tibooburra, you’ll pass through the Grey Range. You climb up then sit on top of a plateau. The water from this plateau runs west and loosely follows Frome Creek. As it flows west, Frome Creek spills into the massive Frome Swamp. You run beside this for a while as you come out from Tibooburra.

Once Frome Swamp is full, the water spills over to the west into Frome Creek and into finally into Lake Pinaroo.

We’re talking over 40km from Grey Range to Lake Pinaroo across some seriously arid country. Little wonder you need huge rains to saturate the ground, then fill Frome Swamp then Lake Pinaroo. Considering Tibooburra’s annual rainfall is about 200mm, you can understand why this is such a rare occurrence. 

In March 2021, just such an event happened. Between 100mm and 140mm of rain in less than 2 days, across a wide band. Combined with earlier rains which had already saturated the ground, Lake Pinaroo filled again.

Lake Pinaroo has a few standout features. Your first glimpse is from the top of a red sand dune through surprisingly dense coolabah trees. Its light grey colour is a stark contrast to the red sand dunes.

Why All The Dead Trees?

Then as you get closer, you’ll notice thousands of dead trees on the flat lake bed. These trees drowned when their roots were covered with water. In fact, some of them bear witness marks on their trunks of the flood level way up their trunks. Standing in the lake bed, it’s hard to imagine this much water being here.

High water mark on dead coolabah tree. Lake Pinaroo, Sturt National Park NSW.
You can see the high water mark on this tree. Hard to imagine this much water.

And what a sight it would be. Sturt National Park comes alive… Lake Pinaroo would be full of life, with millions of waterbirds making the most of this windfall event.

But why is the lake bed and indeed some of low rises within the lake almost white in colour? To answer this, you have to look at where all the sand came from.

During the last ice age, the inland sea retreated and left a vast swathe of sand and sediment behind. Low rainfall and ever-present winds blew huge amounts of sand from the Strzelecki Desert into this area. As it aged, the iron in the sand oxidised to form the distinctive red colouring of the outback. In general terms, the darker the red sand, the older it is.

Looking down at the lake from the sand dunes. Lake Pinaroo, Sturt National Park NSW.
The stark contrast between the white lake bed and the red sand dunes.

Now when a region like Lake Pinaroo floods, you’re talking a long term flood. For example, the lake took about seven years to dry out after the 1974 event. The water actually leeches the iron oxide out of the sand and it re-emerges as white in colour. So you get this pocket of white sand in among the red sand dunes.

Of course, pale clay from the jump-up country also contributes. As you walk onto the lake, you’re heading towards the mouth of Frome Creek. You’ll notice the clay gradually overwhelming the sand . This is because the clay is deposited from the creek mouth and more of it settles closer to the creek mouth.

Keep an eye out for the distinctive lines of coolabahs along the shoreline. Coolabahs seed once a year. The lake took about seven years to dry out after the 1974 flood. You can see where each shoreline was when the coolabahs seeded. The lines of younger trees are quite obvious if you look carefully.

Old Fort Grey Homestead 

Just as you arrive at the shoreline of Lake Pinaroo, there’s an old windmill on the left. Wander over and have a look around. High up on the sand dune near the windmill is a sign showing the high mark of the 1974 flood.

Windmill at Old Fort Grey Homestead. Lake Pinaroo, Sturt National Park NSW.
Windmill at Old Fort Grey homestead.

Lower down the dune you’ll see a jumble of stone. This was the old homestead. It was abandoned after the 1956 flood, when the owners realised the house and surrounding infrastructure was in fact flood-prone.

Apparently the house stood until waves from the 1974 flood undermined the house and it collapsed.

Ruins of Old Fort Grey homestead. Lake Pinaroo, Sturt National Park NSW.
The ruins of Fort Grey homestead. The windmill is further up the dune to the right.

Look around. You’ll find remnants of old yards and fences. And take a minute to reflect on how isolated this station was. While the people who built this house were wise enough to choose a reasonably protected site, they could never have imagined it would one day disappear under water!

Cooking Hearth

A little way onto the lake bed you come across a large scattering of small stones. These formed the base of a cooking hearth used by Aboriginal people. They were the heat beads under the fire and shattered due to the heat.

I haven’t been able to find out any detail about its age. Much of this history has been lost after families were rounded up and trucked to a mission in Brewarrina.

The small stones from the cooking hearth have been exposed over time.  Lake Pinaroo, Sturt National Park NSW.
These small stones from the Aboriginal cooking hearth have been exposed by erosion.

It’s curious how far this hearth is from the shoreline and therefore protection from the elements. I guess the lake bed may have been more heavily vegetated back then. Who knows.

A Well… A Long Way From Anywhere

A couple of kilometres onto the lake is the remnants of a well. A rusty steam boiler still sits there, looking pretty forlorn and lonely out there.

It once ran a walking beam pump, bringing water to the surface with each upstroke. The well was used to water stock but was abandoned after being flooded one too many times.

Remains of a steam boiler at a well. Lake Pinaroo, Sturt National Park NSW.
The vertical steam boiler used to power a balance beam, which pumped water from the well (in the foreground).

Around the well is an old bore casing which would have had a windmill over it, remnants of a tank or trough and the piers of a crutching shed. Working sheep out on this lake bed would have been a hot, shadeless job in the hotter months!

Reamins of water tank and crutching shed. Lake Pinaroo, Sturt National Park NSW.
Remains of a water trough and the piers of a crutching shed.

Sturt’s Tree

Just past the well, you’ll come to the halfway mark. Go right and make your way back to the campground or go straight on to Sturt’s Tree. This adds another 3km to your walk, but it’s worth doing.

We did this in early winter. The cold south-westerly wind did its best to cut us in half as we trudged headlong into the wind.

Walking out to Sturt's Tree. Lake Pinaroo, Sturt National Park NSW.
Head down and into the wind. Sturt’s tree is at the tree line on the horizon. Don’t attempt this in Summer!

And remember how I was saying the clay dominates the lake bed as you move towards the mouth of Frome Creek? Well, Sturt’s Tree happens to be quite close to the creek mouth. So the ground softened and the walk was more difficult… like walking through soft sand in places.

If you’d like to learn more about Sturt’s inland expedition, I highly recommend “Sturt’s Desert Drama” by Ivan Rudolph. It’s a fascinating read.

Quite close to Sturt’s Tree you pass a waterhole. Waterholes like this are the last to dry up in the lake, so provided invaluable water sources for the First People. Sturt actually noted the huts built in this very area.

I wonder what the Aboriginal people thought when 17 white people turned up with horses, bullocks drays, carts, sheep, sheep dogs and a boat! Not only that, they then built a fortification and the strange animals drank much of their precious water.

Nardoo, a bush food found in arid regions. Lake Pinaroo, Sturt National Park NSW.
Nardoo bushes in the lake bed.

We sat there for a while and imagined this spectacle arriving over a sand dune. The First People must have been gobsmacked. What were these strange creatures? Why are they taking all our water?

It would be like you or me sitting out on the front deck when an alien spaceship lobs up the road, lands in your front garden and disgorges a bunch of weird creatures. Then they won’t leave! How do you tell them to bugger off?

Anyway… Sturt’s Tree has been propped up by steel posts. The tree drowned in the 1956 floods, so the steel posts prevent it from splitting in half and falling over. You can clearly see the blaze on the western side made by Sturt or his surgeon John Browne in 1844 and another blaze on the eastern side, made by a surveyor in the 1920s.

Sturt's Tree was drowned in the 1956 flood. Lake Pinaroo, Sturt National Park NSW.
Sturt’s tree looks a bit forlorn these days.

Sturt pushed out from here, “discovering” Cooper Creek. But he never found his inland sea. Little did he realise that he was camped in an inland sea of sorts.

It just wasn’t permanent.

I’m surprised Sturt, his assistant Poole or a young John McDouall Stuart couldn’t read the country better. All the signs are there that this lake fills way beyond the level you’d think was possible. Maybe it hadn’t filled for a long time beforehand. Or maybe they were too fixated on finding their inland sea.

The long walk across the lake bed. Lake Pinaroo, Sturt National Park NSW.
Heading back to the campground from Sturt’s tree. Was good to have a tail wind.

Our return trip back to the loop track was easier, with the wind now threatening to shred our backs. At least we had a tail wind!

A Difficult Way To Build A Fence

Back onto the loop road and you soon come to wooden fence made from coolabah trees. It’s a few hundred metres long and looks like hard work!

The fencers would have first sunk sets of  two vertical posts side by side, about 300mm apart. Then they would cut down coolabah trees and laid them horizontally, slotting them in between the sets of vertical posts.

Remnants of a brushwood fence. Lake Pinaroo, Sturt National Park NSW.
The remains of the wooden fence.

By doing this, they would have formed the wooden fence you can see the remnants of now. This would have been an incredibly labour-intensive way of building a fence. But the pastoralists were simply using the resources they had available.

The Final Act

Pretty soon you’re back in the sand dune country, in amongst the red dunes. The contrast between here and the lake bed is quite stark. Not only has the sand turned a deep red colour again, but you’re actually quite protected.

Surprisingly, the trees are quite thick in between the dunes. We saw some green patches were the water lies after rain. So obviously the trees are tapping into this ground water.

Green patches between the red sand dunes. Lake Pinaroo, Sturt National Park NSW.
Green patches in among the sand dunes.

Up and over the final dune and Fort Grey campground is in sight again. You’ve made it!

Parting Words

Sturt National Park is fascinating. The landscape varies enormously from east to west. For us, the jump-up country closer to Tibooburra and Lake Pinaroo are our favourite parts of this vast national park.

Oh, and Wild Deserts of course!

Dead coolabah tree on the lake bed. Lake Pinaroo, Sturt National Park NSW.
Not a place to be in the middle of Summer…

Lake Pinaroo and Sturt National Park are on Wongkumara and Maljangata country.

For more NSW National Parks you can visit, go here.

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