Cowboy and Indian Alliance protest against Keystone XL pipeline spills into ...

It's a sight not often seen in Washington, D.C.

Dozens of aboriginal and non-aboriginal people holding hands, dancing in a circle in a busy downtown street.

The flashmob round dance was the latest protest by the Cowboy and Indian Alliance. The group has been in the U.S. capital all week protesting the Keystone XL pipeline.

Although largely comprised of American farmers, ranchers and tribal communities, the group also includes a few dozen Canadians.

Heather Milton-Lightening, originally from the Pasqua First Nation in Saskatchewan, has been helping to co-ordinate protests in Washington this week.

'Indigenous rights, whether that's treaty rights, inherent rights or aboriginal title [rights] are the last line of defence in terms of protecting the environment,' she said.

Milton-Lightening is co-director of the Indigenous Tar Sands campaign of the Polaris Institute in Ottawa. She says aboriginal inclusion is key in the anti-pipeline protest.

'The environmental organizations and everyone else that's concerned with climate change or mining or whatever it is, they really need to work with our people in a way that's equitable,' Milton-Lightening said.

The anti-Keystone events began on Tuesday in Washington.

The group staged a protest in front of U.S. Secretary of State John Kerry's home earlier today and yesterday two protesters risked arrest after climbing into the reflecting pool in front of the Lincoln Memorial.

Kerry is tasked with making a recommendation to U.S. President Barack Obama on whether the cross-border pipeline should be approved.

'This is a protest based in the US that is targeting President Obama and his administration but everyone here knows darn well where this oil is coming from.'' - Clayton Thomas-Muller, Idle No More activist

The proposed TransCanada pipeline that would carry crude oil from Alberta to the Texas Gulf coast has been in limbo for more than five years. Last Friday, Kerry's department announced the review period has been extended pending a Nebraska Supreme Court decision on the pipeline route. Now, a decision may not come until the fall at the earliest.

Although the protest in Washington is focused on Americans, Clayton Thomas Muller says it's important that aboriginal Canadians also be here.

'This is a protest based in the U.S. that is targeting President Obama and his administration, but everyone here knows darn well where this oil is coming from.'

Thomas-Muller is originally from Pukatawagan First Nation in Northern Manitoba and now works as a campaigner for the Idle No More movement.

'All roads lead to the same answer. The answer is that the entire economic model of our country called Canada is based on suppressing indigenous rights and based on dispossessing our people from their land so that multi-national corporations can go in there free of any blockades and blockages and extract those natural resources,' he said.

'It's important that we're doing all of this in solidarity with First Nations living in Northern Alberta in the midst of the tar sands.'

The group is expecting 5,000 people to join the protest as they march from the National Mall to the White House tomorrow.

with files from CBC's Meagan Fitzpatrick