On Tuesday afternoon the Canadian government approved the expansion of a pipeline that will triple the flow of tar sands oil between Alberta and an export facility on the Salish Sea.

An environmentalist who spoke to the Seattle Times' Lynda V. Mapes characterized the Kinder Morgan Transmountain pipeline expansion as "Standing Rock North." There's good reason to say so: the pipeline expansion will carry 890,000 barrels of oil per day. That's 420,000 more barrels than the Dakota Access pipeline and 60,000 more barrels than the proposed Keystone XL pipeline.

The new pipeline expansion will also increase the number of oil tankers in the Salish Sea by a factor of seven. And those tankers will be carrying a type of oil that is particularly destructive to marine environments. Tar sands oil, unlike the type of crude fracked from the Bakken, is heavy and sinks to the ocean floor. It's nearly impossible to clean up, and environmentalists say that the traffic from the oil tankers alone will further endanger Puget Sound's resident killer whale populations.

But the Standing Rock North characterization holds true for another reason, too. Tribes in British Columbia and Washington State are on the front lines of this fight, and they may be the only people with the standing to stop the continued destruction of a body of water stewarded by both Canadians and Washingtonians.

The Tsleil-Waututh Nation in British Columbia has been fighting the Kinder Morgan pipeline for years. The pipeline terminus is located directly across a waterway from tribal land, just north of Vancouver, and tribal leaders say that approving the pipeline infringes on Aboriginal rights. "It would expose our people and our territory to serious risks associated with oil spills and other concerns related to marine shipping, all of which we have communicated to your representatives and substantiated with scientific studies," Tsleil-Waututh Chief Maureen Thomas wrote to the federal Canadian cabinet three days before they approved the pipeline.

Four Washington nations—the Lummi Nation, the Suquamish Tribe, Swinomish Indian Tribal Community, and Tulalip Tribes—are also invested in blocking new oil tanker traffic caused by the pipeline expansion. Three years ago, all four tribes stood in front of Canada's National Energy Board and explained that expanding the pipeline would threaten their fishing livelihoods.

Swinomish Indian Tribal Community chairman Brian Cladoosby, who told the board that an oil tanker had once plowed through a Swinomish fisherman's net, said that he wasn't just there on behalf of Native communities. "We are speaking on behalf of all the citizens that live here in the Salish Sea," he said. "They all should be concerned."

US tribes don't have the same legal standing with the Canadian government that First Nations do. But Earthjustice attorney Kristen Boyles says that the Canadian government's pipeline decision still ignored US treaties between tribal nations and the US government.

"There is no obvious next step in the path for US tribes to challenge a Canadian pipeline decision," she said. "However, the tribes and First Nations in Canada are very opposed to this, especially those around the Salish Sea area, and the US tribes will be working as closely as possible in what I assume will be challenges to this final decision."

In response to the Canadian government's decision, Tulalip Tribes chairman Mel Sheldon said in a statement that Prime Minister Justin Trudeau "made a decision that carries with it potentially catastrophic consequences for our Treaty-reserved rights to fish and harvest in our usual and accustomed territories."

Fred Felleman, whale biologist and Port of Seattle commissioner, says he believes tribes are the only groups left that have the power to challenge the Canadian government's decision.

"Just like almost all other fossil fuel projects in the country, it's all up to the tribes and the First Nations," Felleman said. "It's going to be their legal standing that's going to keep us from running the whales to extinction. The Tsleil-Waututh Nation are in ground zero."