As an arts patron and piano teacher in her early 60s from one of Hobart's wealthiest suburbs, Brenda Hean was an unlikely environmental activist.
But the avid bushwalker was captivated by the distinctive pink quartzite beach at Lake Pedder in Tasmania's south-west and was outraged by the Tasmanian government's plans to flood it for hydro-electricity generation in the late 1960s and early 1970s.
Brenda Hean's fight to save Lake Pedder would ultimately lead to her mysterious disappearance but, 50 years on, the campaign for the lake is taking off again.
Lake Pedder's 'incredible beauty'
"Pedder was just the jewel of the south-west," said Dick Friend, who first walked into Lake Pedder in 1972.
"It was just most unusual to have a beach that's vastly bigger than Bondi Beach in the middle of a wilderness in the mountains, and a unique ecosystem.
"It was that uniqueness and the absolutely incredible beauty that struck everyone that went there, and that created such a campaign out of very little awareness or knowledge at the beginning."
By the time 19-year-old Dick Friend first saw Lake Pedder, Tasmanian Premier Eric Reece's contentious plan to flood the lake for a hydro scheme was underway, with the Serpentine Dam closed off and the reservoir filling.
The plan was facing stiff opposition from environmental protesters, with their campaign giving birth to the world's first green political party — the United Tasmania Group — for which Brenda Hean stood as a candidate at the 1972 state election.
She was unsuccessful but undeterred, and Dick Friend took Brenda Hean to Lake Pedder for a beach vigil as the waters rose.
He describes twisting through "impenetrable" trees on the side of the lake as it got dark, and deciding to erect a tent over their dinghy as it was wedged in between branches.
"So we're in a boat, up a tree, on a lake, in a tent, four of us in a tiny boat," he said.
"It showed you how brave Brenda was to go on any adventure possible."
'Save Lake Pedder' campaign
After weeks of protest, the beach vigil had to be abandoned in the face of rising waters and Brenda Hean decided to take a radical step to get the fight for Lake Pedder to the mainland.
She was convinced to fly to Canberra with pilot Max Price, in his vintage Tiger Moth biplane, to meet politicians and sky-write "Save Lake Pedder'' over Parliament House in Canberra.
Brenda's niece, Celia Watchorn, recalls watching them take off from Hobart on September 8, 1972.
"Max and Brenda, they were both passionate about what they were doing — it was very much: 'What more can we do to save this iconic place?'" she said.
"There was a small group of us, mostly ladies and a few fellas, reporter, cameraman … just to farewell this little biplane off on its journey.
"There was no 'hurrah' or anything more than that really. And their little Tiger Moth just flew off. So that was quite a moment."
But within hours, Brenda's family received a phone call to say there'd been no further sighting or contact since the pair had radioed into St Helens, on Tasmania's east coast.
A 10-day sea and air search found no trace of the plane.
"It was just disbelief, shock," Ms Watchorn said.
"And that silence has continued to this day, amazingly."
Questions and suggestions of foul play soon emerged, with evidence the airport hangar had been broken into.
The emergency locator beacon that should have been on the plane was later found at the back of the hangar.
Dick Friend said the pair had also received threats.
"But, you know, without finding a wreckage, you can't really prove anything," he said.
New campaign taking off
Five decades on, the disappearance remains unsolved and the original Lake Pedder is now 20 metres underwater.
In a statement, Hydro Tasmania said that combined with Lake Gordon, it is the largest storage of water in Australia and contributes approximately 13 per cent of Tasmania's total power generation.
But the push to save Lake Pedder continues, with a campaign to restore the lake to its pre-1972 levels.
Fifty years to the day since Brenda Hean and Max Price took off, a new generation of Lake Pedder activists are retracing their original route in another Tiger Moth plane.
Taking off from Hobart on Tuesday, the plane has a roster of co-pilots until it lands in Canberra on Saturday.
One of those is Brenda Hean's great-great niece, Charlotte Ditcham.
"I want to spread the message about my great-great aunt and what she tried to do, and finish off what she did," she said.
"I think I'm just doing it to honour my family really, and for her, even though I didn't get to meet her — I just want to do what I can."
The Tiger Moth will have a support plane, piloted by Brenda's great-great nephew.
Dick Friend, who is now on the Lake Pedder Restoration committee, said they would be met with a third plane that would perform the skywriting in Canberra.
"Rather than 'Save Lake Pedder', this time it will be 'Restore Lake Pedder' … to complete the task that was embarked upon 50 years earlier."
The group wants the massive reservoir drained, and the original lake and beach restored.
It's not the first push for restoration, but past and present Tasmanian governments have rejected the idea.
Energy Minister Guy Barnett has described the campaign as "ideological".
"That would be an economic and environmental vandalism to even consider that effort," he said.
"This would take our renewable energy credentials backwards."
Brenda Hean's niece Celia Watchorn is undeterred.
"[Brenda and Max] both went, hopefully quickly, with their flags flying," she said.
"And the strength of the message that has continued on from their sacrifice is quite extraordinary.
"It's not going to go away in a hurry at all."
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