WASHINGTON — Dallas Goldtooth peers into the modest crowd gathered before him in front of the White House on a bitter cold mid-winter day. Some hold signs boldly stating “KXL will spill” and “reject to protect,” others stand solemnly, listening to speakers and nodding as they rail against the sharply contested Keystone XL pipeline.

Goldtooth, a member of the Great Sioux Nation, is the Keystone XL campaign organizer with the Indigenous Environmental Network, an organization founded 25 years ago out of the “wounds inflicted upon the earth from the collective greed of humanity.”

Goldtooth was contacted earlier this week following President Barack Obama’s veto of legislation passed by Congress that would clear the way for construction of the pipeline.

“But the fight is not over. We need an outright rejection of the KXL permit,” Tom Goldtooth, Dallas’ father and the executive director of the IEN, said in a statement. “That would be the final nail in the coffin for Keystone XL.”

Though Congress approved legislation that would greenlight construction on the pipeline, each chamber appears short of the two-thirds majority required to override a presidential veto. Even so, the Senate began taking procedural steps this week to attempt an override, giving new life to the battle on Capitol Hill.

The fight against – and for – the pipeline also continues unabated in the nation’s heartland. The Indigenous Environmental Network organizes demonstrations and raises awareness in campaigns to stop what activists see as environmental injustices against American and Canadian Indians.

“We’re trying to protect Mother Earth and helping indigenous communities in that fight,” Goldtooth said during a phone interview.

“The veto was and is a small victory in a greater fight to stop the tar-sands pipeline from being built,” Goldtooth said. “We are going to continue to pressure the president to outright reject the pipeline.”

Despite his veto, the president could yet decide to approve the pipeline of his own accord, something the network is l wary of. If built, the pipeline would carry 830,000 barrels of crude oil each day from the Alberta tar-sands through six states, connecting in Steele City, Nebraska to another line that would transport it to the Gulf Coast of Texas.

Several government investigations have looked at the impact of the pipeline. But the indigenous network and other Native American groups say they have not been properly consulted, in disregard of their rights as sovereign nations and in violation of the Fort Laramie treaties of the 19th century.

“Tribal nations have not been respected,” Goldtooth said. “We have to stand up against these instances where we have not been consulted on such things, where they’ve failed to acknowledge our treaty rights and our inherent rights as native peoples.”

To this end, TransCanada Corp., which filed the application to build the 1,179 mile long pipeline in 2008, has said it would provide “tribal monitors” for each construction team to preserve the cultural integrity of tribes that have contact with the pipeline.

In a statement on their website, TransCanada says it “strives to create employment opportunities for Aboriginal and Native American communities along our pipeline routes,” citing the more than $50 million the company invested in contracting and hiring in these communities across North America. The company projects the pipeline would create 42,000 new jobs, all of which would be available to Native Americans.

Though the pipeline narrowly avoids running through tribal lands in Montana, South Dakota and Nebraska, home to many Great Plains tribes including the Great Sioux Nation, a spill could result in the contamination of the Ogallala aquifer, depriving 80 percent of the population, both native and non-native, of clean drinking water.

“The majority of tribal nations pull fresh water from [the aquifer],” Goldtooth said. “Should a spill occur, it puts their safe drinking water at a terrible risk.”

Initially, the State Department concluded that the pipeline would have little “adverse environmental impact,” though the assessment was later discarded due to a conflict of interest between the drafters and TransCanada. In 2013, it was found that the aquifer could suffer in the event of a spill.

“The native people are very skeptical when it comes to statements made and actions made by US government, and rightfully so,” Goldtooth said, referring to the contentious history between tribal people and the United States government since the country’s inception.

Opposition to the pipeline extends beyond the network, with Rosebud Sioux Tribal President Cyril L. Scott publically calling the House’s approval in November an “act of war” against all native people. Non-native environmentalists also oppose the pipeline as tar-sands oil refining emits three times more greenhouse gases than conventional gasoline, according to a report by Friends of the Earth, an environmental group.

The fight goes beyond the pipeline; the network has worked with native people in Alberta, primarily the Dene and Creek nations, on their attempts to reject tar-sands development throughout the past decade. By opposing Keystone, Goldtooth says, they can help those First Nations people by putting financial pressure on companies operating out of Alberta.

“Our hope is that by shutting down these transport routes and means to get the oil to the market… we can help the fight against tar-sands development in that area,” Goldtooth said.