BISMARCK, N.D. — Two Native American tribes suing to stop the Dakota Access pipeline have asked a judge to head off the imminent flow of oil while they appeal his decision allowing the pipeline’s construction to be completed.

US District Judge James Boasberg last week rejected the request of the Standing Rock and Cheyenne River Sioux tribes to stop construction of the final segment of the pipeline under Lake Oahe, a Missouri River reservoir in North Dakota from which the tribes get their water.

The pipeline’s developer, Texas-based Energy Transfer Partners, expects to have the pipeline filled with oil as early as this week.

The tribes maintain that an oil pipeline under the lake they consider sacred violates their right to practice their religion, which relies on clean water. In his decision last week, Boasberg said the tribes didn’t raise the religion argument in a timely fashion and he questioned its merits.

Cheyenne River attorney Nicole Ducheneaux on Friday appealed the ruling to a US appeals court, and asked Boasberg to prevent the flow of oil until the appeal is resolved.

Associated Press