Over the next rise the seemingly never-ending fence line is eventually broken by a rickety old farm gate. Adjacent to the gate is an ancient gum tree, its gnarly trunk and tortured branches testimony to many a harsh Riverina summer. It must be hot – the lone kookaburra perched in its canopy can't conjure up enough energy for even the briefest of chuckles.

The gum offers welcome shade and while we pluck copious corkscrew burrs from our socks, between sips of water, Ambrose points into the paddock and proudly announces "this is it, over there is where Tom Roberts painted Shearing the Rams".

Although the landscape in this paddock on the outskirts of Corowa has changed little since Roberts visited in 1888, unfortunately the shearing shed captured in his famous painting, arguably Australia's most loved, is long gone. "Its foundations were undermined by rabbits so it was torched in the 1960s," laments Ambrose, pointing over the fence to the location in the paddock where the shed once stood.

It's astounding that there's no sign to indicate this is where Roberts spent over three months in the spring of 1888 preparing more than 70 sketches for his masterpiece, which will feature in this summer's blockbuster at the National Gallery of Australia. To anyone without inside knowledge, it just looks like just any other paddock in the country.

However, I'm not going to argue with Ambrose, for if anyone knows exactly where the shed stood it has to be her. Her grandmother, Susan Bourne, was an unlikely star in the painting.

"Most people naturally think the tar boy [who applies tar to the skin of sheep cut during shearing] in the centre of the painting was a boy, but it actually was my grandmother," says Ambrose, a life-long resident of Corowa.

"She was asked to help create atmosphere by sweeping the floors of the shed and in exchange for that he included her in the painting," explains the charming octogenarian, who adds "I think Roberts also put her in the painting for another more meaningful reason."

"Her face was young and fresh and was a metaphor for the push for Federation, a new nation about to come into being" says Ambrose, who reflects on a number of stories her grandmother told her about Roberts' stay at the farm which was then part of the extensive Brocklesby Station.

"At some stage during the painting, Roberts left his paints in the shed, so Susan and her sisters decided to paint some of the shed, including its steps and railings," smiles Ambrose, adding "I guess kids will be kids."

"Apparently in the mid-1900s the owners of shearing shed souvenired a piece of timber splashed with paint from the shed, framed it and put it on their mantelpiece, thinking they had a Roberts original," muses Ambrose, who adds, "it was probably just the work of my grandmother and her cheeky sisters."

Across the laneway running alongside the paddock is a small wooden shelter at the entrance to Redlands Hill Park, a reserve managed by the local council and Landcare group. In honour of Roberts, the hut was designed as a mock-up of part of a shearing shed. I take a peek inside. It contains information on the plants and animals you'd expect to see in the reserve but inexplicably no mention of Roberts, whose iconic work was painted just metres away.

For any acknowledgement of Roberts' connection to Corowa you have to head into town to the Federation Museum. However, even then you have to find your way past an eclectic collection of exhibits including a birthing chair once owned by a local doctor and an old washing machine before you reach a modest display about Roberts which identifies all the local characters in the painting, including Ambrose's grandmother, and also boasts a couple of ageing photos of the original shearing shed.

A booklet at the front counter highlights a correspondent to the Corowa Free Press on November 29, 1889, who waxed lyrical about Shearing the Rams, and who by his last statement, could well have given Nostradamus a run for his predictive prowess. "It looks so life-like that you cannot but wonder at the amazing skill of the master hand that did it … I do not hesitate to say it would grace the National Gallery."

We eventually retreat from the afternoon heat and return to Ambrose's modest bungalow perched above the banks of the languid Murray River in south Corowa. In her lounge room, while flicking through a book of Roberts' prints, Ambrose stops me at the page featuring A Break Away!, which depicts a drover trying to stop sheep stampeding into water.

Despite the immortalisation of her grandmother in Shearing the Rams, Ambrose drops a bombshell, revealing that A Break away! is actually her favourite Roberts' painting.

"It's incredible how he captured the leaping of the sheep and the dog getting rolled," she says, adding, "he also painted it somewhere near Corowa but I'm not exactly sure where."

With your Akubra-clad columnist well and truly in the grips of Tom Roberts' fever, Ambrose's statement is like a red rag to a bull.

Armed with Ambrose's book open at the page featuring A Break Away! and an extra can of insect repellent, I head back into the bush.

How hard can it be?

Next week: Don't miss part 2 of my journey in the footsteps of Tom Roberts, when I go in search of the exact location depicted in A Break Away!, the painting which many, including the artist himself, believed was his best work.

Corowa: This pretty Riverina border town is about 4 hours' (400 kilometres) drive south-west of Canberra via the Hume Freeway (M31) and B400. Before it was razed by fire in the 1960s, the shed featured in Shearing the Rams was located in a paddock around 13.3 kilometres from the centre of town via Redlands Road and Tom Roberts Road. The paddock isn't signposted and although originally part of Brockelsby Station, is now part of Killeneen, a private property not accessible to the public.

Federation Museum: 56 Queen Street, Corowa. Open Saturdays and Sundays, 1pm-4pm, or by appointment. $4 per adult. Ph: (02) 6033 4041.

The exhibition: Tom Roberts, this summer's blockbuster exhibition at the National Gallery of Australia, opens on December 4 and runs until March 28. It features 133 of his paintings, pastels, drawings, prints and sculptures and includes both national narratives Shearing the Rams and A Break Away!. Tickets available from Ticketek or at the gallery. More: nga.gov.au/roberts or phone 6240 6411.

Contact Tim: Email: timtheyowieman@bigpond.com or Twitter: @TimYowie or write c/-The Canberra Times, 9 Pirie St, Fyshwick. You can see a selection of past columns at: canberratimes.com.au/act-news/by/tim-the-yowie-man.

Where in Canberra?

Clue: While recently walking through Telopea Park, John Hyslop was perplexed to see this historic photograph on a heritage sign complete with caption identifying the location as a as "an aerial view of Manuka Oval, Manuka Pool and part of Telopea Park in the right bottom corner". I agree with Hyslop that the caption is incorrect and that "it's nowhere near Manuka", so to claim today's prize you need to identify the correct suburb shown in the photograph. As an extra clue, both Hyslop and I believe it was snapped in the 1950s, not 1921 as indicated on the sign.

Degree of difficulty: Hard

Last week: Congratulations to Jack Palmer of Watson who was first to correctly identify last week's photo (inset), sent in by Evan Croker as the Royal Australian Navy Memorial Sailors and Ships – Interaction and Interdependence on Anzac Parade. Palmer just beat Mick Ginman of Lyons to the prize who was "mighty sure of the answer", because as an apprentice he "used to regularly change the lights inside the memorial".

How to enter: Email your guess along with your name and address to timtheyowieman@bigpond.com. The first email sent after 10am, Saturday, November 21, with the correct answer wins a double pass to Dendy cinemas.