Judge denies tribes' motion seeking to temporarily halt Dakota Access pipeline Oil could flow through the pipeline as soon as next week.

 -- A federal judge in Washington, D.C., denied a last-ditch effort by the Cheyenne River Sioux and Standing Rock Sioux Tribes to halt the flow of oil through the Dakota Access pipeline on Tuesday.

The ruling -- by U.S. District Court Judge James Boasberg -- means oil could be moving through the controversial pipeline as soon as next week.

The tribes had asked the court for a preliminary injunction last month -- following the Trump administration’s decision to grant an easement for the pipeline’s final stretch, which runs under the bed of Lake Oahe, a federally regulated reservoir that is a source of drinking water for both tribes.

Chase Iron Eyes, the lead counsel of the Lakota People’s Law Project, called Tuesday's ruling “unjust and unacceptable.”

The pipeline had been stalled since last summer as tribal members and other protesters camped out near the construction zone and as the Obama administration deliberated over whether to grant the easement -- ultimately declining to do so -- in early December.

But on his second weekday in office, President Trump signed a presidential memorandum aimed at advancing approval of the pipeline, to the extent permitted by law. Two weeks later, the Army Corps of Engineers announced that it was granting the easement and also canceling a more thorough environmental review of the project that had been initiated two days before Trump’s inauguration.

The Corps asserted that a previous environmental assessment -- completed last July with a finding that the pipeline would have no significant impact on the human environment -- was sufficient to grant the final permit for the pipeline to cross at Lake Oahe.

Yet the tribes have long maintained that earlier review paid little heed to their concerns and historical treaty rights.

“Once again, the federal government and the Army are treating the original inhabitants of this land as though we are less than human, as though our lives and lands are something to be ignored and discarded in the never-ending quest for profit,” Iron Eyes said in a statement.

The four-state Dakota Access pipeline is built entirely underground and is designed to transport crude oil more than 1,000 miles from the Bakken production area in North Dakota to an existing distribution center in southern Illinois. Texas-based Energy Transfer Partners, the company constructing the pipeline, had argued against the preliminary injunction in court filings, asserting that it stood to lose tens of millions of dollars if the pipeline experienced any further delays.

Judge Boasberg's ruling today is a narrow one, focusing solely on a claim raised by the Cheyenne River Sioux under the Religious Freedom Restoration Act. The tribe argued that the mere existence of the pipeline at Lake Oahe would “desecrate those waters upon which the Cheyenne River Sioux tribal members rely for their most important religious practices.”

Energy Transfer Partners called those claims “a last-ditch desperation throw to the end zone” that “could not conceivably meet the required showing of irreparable harm needed to support a restraining order or preliminary injunction.”

The company informed the court earlier this week that construction is progressing and the pipe could be carrying oil by sometime next week.

“That’s obviously disappointing and troubling,” said Jan Hasselman, an attorney for the Standing Rock Sioux. “It does not, however, change anything about the legal case.”

The tribes anticipate that court will rule in April or May on their broader challenges to the pipeline, which include allegations that the project was approved in violation of treaty rights and contrary to environmental and administrative law.

Boasberg has set an expedited scheduled to hear those arguments and has indicated that if he rules in favor of the tribes, it is possible the company could be ordered to stop the flow of oil.