To the indigenous Chippewas, Ontario's Thames River is central to life and is to be treated with spiritual reverence. Which is why they are taking their right to protect it all the way to Canada's Supreme Court.
Myeengun Henry, Chippewas band councilor for the Thames First Nation, has been here before. But he struggles to pick out the exact location of the pipeline on the bank of the Grand River.
The only evidence of Line 9B - a 639-kilometre section of pipeline carrying oil from the Alberta tar sands - are five bright orange posts marked with the words "danger" and "petroleum pipeline."
"It's my responsibility to help keep this land healthy," Henry says, standing on a snow-covered embankment overlooking the river. "As an Aboriginal person, or as a human, we have to do something about this. We can't let this continue."
Invisible it may be, but Thames First Nation is convinced the pipeline is a ticking time bomb threatening the local environment and way of life. Now, they are taking their battle against it to Canada's Supreme Court.
In March 2014, the National Energy Board (NEB) of Canada approved an application from energy company Enbridge, which has operated the pipeline since 1976, to reverse the flow of oil through Line 9B to transport Canadian tar sands oil.
Today, the pipeline carries oil from the Alberta tar sands, across the province of Ontario, and up to a terminal in Montreal. The NEB has also approved Enbridge's request to boost the line's capacity to 300,000 barrels of oil per day.
The Chippewas of Thames First Nation say they were never consulted on the plans. Under the Canadian Constitution, they government has a "duty to consult" and accommodate indigenous peoples when a project may impact their aboriginal or treaty rights.
The community believes the pipeline is unsafe - and a spill could devastate the Thames River and its watershed area, as well as many other waterways across the province.
A spiritual relationship
"We don't understand how an old line carrying now up to 300,000 barrels per day can actually accommodate that without breaking someplace," Henry says. "There is no way that they can tell us that line is safe, and we need to protect the land."
The river plays a central role in life here.
"The Thames River near London (Ontario) is our main source of water and fishing and hunting area," Henry says. "The river has a spiritual relationship to our people and we have the responsibility of keeping the river healthy and clean."
Campaigners against the pipeline fear that great respect and reverence isn't shared by the fossil fuel industry.
Andrea Harden-Donahue, an energy and climate justice campaigner at the Council of Canadians, a social justice group, said tar sands oil is particularly dangerous near waterways.
"Much of what's being exported right now is called diluted bitumen, which presents heightened risks when it's spilled, particularly in waterways, because it sinks faster than conventional oil and sticks to everything it touches," she told DW.
Canadian Prime Minister Justin Trudeau, who came into office last November, has pledged to meet the climate goals set out during the Paris Summit last December. But he also said recently that pipeline revenues can help Canada transition to a green economy.
Activists say the pipeline is a test of the new Trudeau government's commitment to the environment and First Nation rights
Harden-Donahue says the fact that the government has announced plans to create a national climate policy is a promising sign.
"But the fight is far from over. In fact there (are) still projects in play that could see a dramatic expansion of the tar sands, and here in Canada social movements are doing their best to make sure that they are not expanded."
Jobs and energy security
Enbridge argues the pipeline will create jobs and safeguard Canada's energy supply.
Company spokesperson Graham White told DW Enbridge is "committed to fostering a strengthened relationship with the Chippewas of the Thames First Nation built upon openness, respect and mutual trust".
He added that there is a limit to what the company can say publicly since the matter is before the courts
Climate commitments put to the test
But Mike Hudema, a climate and energy campaigner at Greenpeace Canada, said the pipeline issue is a test of the new government's commitment to the right of First Nations peoples - and reducing Canada's carbon footprint.
"The science is very clear that we can't have more pipeline construction, we can't be unlocking vast regions of new carbon emissions at a time that we need drastic reduction," Hudema told DW.
Canada's economy is heavily dependent on fossil fuels and among the world's biggest emitters of CO2.
"The question really is: what is Canada going to decide to do?" says Hudema. "Are they going to continue to be the climate laggard that is going to fall behind other nations because of their dependence on this devastating resource, or are they going to be the world leader that the globe really needs to see?"
Meanwhile, the Chippewas of the Thames have partnered with an Inuit hamlet named Clyde River in its appeal to the Supreme Court. Clyde River says it was not consulted on a plan to conduct seismic testing in the Canadian Arctic.
The Supreme Court will hear the appeal on November 30.
"We'll have an opportunity to have a voice that we've been unable to use for generations when those big decisions are made,” Henry says. "So I have high hopes."
The National Energy Board said it is considering how it will approach the Supreme Court case.
"All National Energy Board decisions are subject to independent and impartial judicial oversight, generally through the Federal Court of Appeal and Supreme Court of Canada, and the Board is bound to act in accordance with the courts' decisions," a spokesperson for the NEB told DW.