'This is pretty well pure rainforest,'' notes Bob Brown as the seaplane sweeps over the junction of the Gordon and Franklin rivers, deep in remote south-west Tasmania.
It is, and it nearly wasn't.
Bob Brown: the Franklin blockade
Lightning hits Empire State Building
Protesters attempt to save century old tree
Another icy commute in store for Melbourne
Koalas: Not so dumb after all
Sunny weather for Sydney
Wildfires rage in record heat
Giant trees cloned to fight climate change
Bob Brown: the Franklin blockade
Bob Brown returns to the Gordon River in Tasmania, 30 years after the Franklin River blockade.
From above, the temperate myrtle-beech and Huon pine of the Tasmanian Wilderness World Heritage Area create a royal green blanket that covers all but the sharpest peaks and is cut by snaking blue-brown waterways, shining and narrow.
That it still looks like this is in part due to a decision Australians made 30 years ago today.
Picking up on a campaign that took hold in mainland swing seats, prime minister-elect Bob Hawke's first commitment on election night was: ''The dam will not be built.''
He blocked the creation of a 100-metre-high rockfill dam wall - the biggest of its type planned in Southern Hemisphere - that would have flooded 25 kilometres of the Franklin River and drowned the surrounding forest.
The Tasmanian Liberal government challenged the decision in the High Court, claiming states' rights, but lost a 4-3 judgment. By then, Dr Brown - the initially accidental public face of the bid to save the river - had entered the Tasmanian parliament and begun a three-decade political career.
Overlooking the site of the Franklin blockade for the first time in five years, the former Greens leader says it strikes him that the groundbreaking campaign - the first to successfully thrust a seemingly far-flung environmental issue on to the national stage - would fail if launched today
While he believes public concern for the environment is greater than ever, the political value placed on untouched areas far from where most Australians live has evaporated, for now at least.
''The river would be gone,'' he says. ''The power of the resource extraction industries is running politics. Just in December, the Gillard government tried to hand back legislative power to the states, and I predict Tony Abbott will go further if he is elected.
''We are in an extraordinary situation where we don't take pride in our world heritage properties the way other countries do.''
Dr Brown first saw the Franklin in 1976 after accepting an invitation to go on a rafting trip from Launceston forester Paul Smith. Famously, it changed his life.
After a brief but mildly alarming encounter with a trio of fishermen armed with a large gun ("Deliverance had just come out and we had that very much in mind"), they did not see another human, or barely a sign of human impact, during the 11-day journey.
''It was day after day of waterfalls and side canyons, each of which was a marvel. There were rainforests, fungi, leatherwood blossoms, platypuses, sea eagles and cormorants. Then we got to the Great Ravine, a spectacular deep gorge 500 metres deep with the big rapids,'' he says.
It was a transforming experience. ''I was just transported by the remoteness and the wilderness of that country. And then we came down the Franklin, turned right into the Gordon River and suddenly there were jackhammers, explosions out of adits, helicopters, motorboats,'' he says.
''Suddenly we'd come out of this entranced journey with nature and run into a cacophony down there and I was struck by the seriousness of what was going to happen.''
The campaign built slowly, but became a full-time occupation in 1978, when Dr Brown gave up medicine and moved to Hobart. It peaked in summer 1982-83 when the Wilderness Society forged new ground in environmental campaigning in Australia by launching a mass non-violent protest, with more than 2000 people arriving at the west coast town of Strahan in an attempt to block the works.
They had little direct success, but more than 500 were arrested and the clashes with police and Hydro-Electric Commission workers received national coverage.
Dr Brown, who spent 19 days including Christmas 1982 in Risdon Prison, says luck played a part. Rain delayed construction, and the road being built for the bulldozers collapsed. The arrival of British botanist David Bellamy brought international attention. The Labor premier opposing the project, Doug Lowe, was rolled by his own party, but not before signing a letter successfully requesting World Heritage listing. And on the day the election was called Mr Hawke rolled Bill Hayden as Labor leader, who was less sympathetic.
''So much of the whole thing hung by a thread,'' Dr Brown says.
Beyond the protection of the river, one of the lasting impacts of the battle over the Franklin was the introduction of strict penalties designed to stop protesters. Dr Brown says the legacy of the laws used to charge the protesters - that they could not ''lurk, loiter, hide or secrete'' - have been mimicked across the country.
Today, nearly every environmental campaign from the Kimberley to the Tarkine is said to be ''as big as the Franklin". Dr Brown says none is the same - ''It was the first of national significance, and you can't do that again'' - but that the opposition to the proposed James Price Point gas hub comes closest.
''Last week 20,000 people marched in Fremantle about this, and yet it received no coverage,'' he says. ''Once it is gone you can't get it back. If ever there has parallels to the Franklin it is that.''