It has been 40 years since the first images emerged of protesters blocking the path of bulldozers to stop the logging of rainforest at Terania Creek on the New South Wales north coast.

The protest is regarded as a watershed moment in Australia's environmental movement and cited as the first time people physically defended a natural resource.

While the fight to save the rainforest reached its climax in August 1979, the story began several years earlier when a young couple from Melbourne moved to a single-room cabin bordering the rainforest in Terania Creek.

Hugh and Nan Nicholson said they were drawn to the incredible beauty of the area and were shocked to learn the following year that the Forestry Commission planed to clear-fell the forest.

"Our involvement was very sudden, very abrupt," Mrs Nicholson said.

"We had no experience, we were very young, but we felt we couldn't let this go, we had to try to do something."

Over the next four years, the Nicholsons said their efforts to halt the logging escalated from writing letters and submissions and lobbying politicians to hosting hundreds of protesters and being at the coalface of the fight.

"We found there were many other young people who had just moved to the area and they also were appalled at the idea of this beautiful forest being flattened," Mrs Nicholson said.

"So we quite quickly got into a group that was going to fight it, and that was the start of years and years of battle."

'Not so peaceful' protest say loggers

While the demonstrators' intentions were "non-violent, peaceful protest", not everybody held to that ideal.

Death threats were made and received by each side.

Even though Hurfords Hardwood had nothing to do with the Terania logging operation, the family's South Lismore mill was burnt to the ground.

The company who held the licence for the coupe at Terania Creek was the Standard Sawmilling Company from Murwillumbah.

John Macgregor-Skinner, the production manager at the time, said the toll from protests put an "astronomical" strain on his workers and family.

"We had tractors sabotaged, people threatened [with] chainsaws, trees spiked, bridges sabotaged and the like," he said.

"From a personal perspective, we received telephone calls to say that my wife was going to get raped, they knew where the kids were going to school and they weren't going to come home tomorrow.

"That happened on several occasions to the point that we had police protection and I had a direct line to the police inspector.

"Nothing did eventuate, but by gee you don't know."

Mr Macgregor-Skinner said the protest also had a detrimental impact on jobs on the NSW north coast.

"Terania Creek was only a very, very small part of our operations," he said.

"But what eventuated out of Terania Creek closed down the mill."

Mr Macgregor-Skinner estimates 600 jobs were lost in the region when Neville Wran, then New South Wales premier, made the historic 'rainforest decision' in October 1982, removing about 100,000 hectares of forest from timber production.

Legacy of saving the 'big scrub'

Bundjalung woman Rhoda Roberts was only young when the Terania Creek protests took place, but she can remember her late father, Pastor Frank Roberts, talking about the new arrivals who were eager to save the environment.

She said at the time traditional owners were living under the Protection Act.

"We didn't really have a voice. You've got to remember there were curfews, they were taking kids.

"People were very frightened, so to have a group of people who arrived on country and were determined to love that environment, from our perspective, was incredibly new."

Ms Roberts said the big scrub, which includes Terania Creek, is a 'storybook' place where knowledge is exchanged among generations.

"I'm indebted now because my children and the coming children … when we travel our territories, we still have a sample of land that we know has been there since time immemorial," she said.

"I pay my greatest respects to everyone who was involved in Terania Creek because you saved country for us, and we are all benefiting from that."

Looking back through the lens

Much of what transpired at Terania Creek was captured by filmmakers Paul Tait and Jeni Kendall who moved to the region in 1978 to grow avocados.

They remember taking their four-month-old daughter Emma to see the rainforest and being awed by the beauty.

"We ended up losing our daughter," Ms Kendall said.

"We felt like that was her special place so we had to go and defend the memory of that."

The pair had planned to take part in the protest for a day, but when they saw the scale of it, they knew it would be a much longer endeavour.

The images they recorded and sent back to their former colleagues at the ABC helped shift public opinion, and their documentary Give Trees a Chance received numerous accolades.

"It was definitely a milestone for us because we went on to make films around the world for the next 20 years on the environment and endangered peoples," Ms Kendall said.