Earlier this month, a federal judge stunned the U.S. energy sector with an order to shut down the Dakota Access pipeline. Environmentalists hailed it as the first time a fully operating system had been forced to close by a legal challenge. As it turns out, it was actually the second time an oil pipeline was ordered shut in a matter of four days.

On July 2, a lesser-known conduit called Tesoro High Plains was ordered shut for the first time in its 67 years of operation. Together, the two pipelines ship more than one-third of crude from America’s prolific Bakken shale formation to market. Their travails signal the ebbing of the oil industry’s sway in the U.S. heartland and underscore the growing heft and savvy of challengers who’ve become emboldened to demand higher compensation and safeguards.

“In the past, it was a shotgun approach of challenging pipelines,” said Brandon Barnes, an analyst for Bloomberg Intelligence. “Now, the resources are more plentiful and the challengers are far more nuanced and sophisticated in their approach.”

The stakes are high. If the shutdown of both pipelines proceeds, it would force the region’s drillers to turn to more expensive options to ship their oil — or shut in production altogether, just as the entire oil industry is reeling from depressed prices that have pushed a steady stream of producers into bankruptcy.

The outlook for the U.S. pipeline industry has perhaps never been more uncertain. Earlier this month, Dominion Energy Inc. and its partner Duke Energy Corp. announced they were no longer moving forward with their $8 billion Atlantic Coast natural gas pipeline after years of delays and ballooning costs. In the ensuing 24 hours, the Supreme Court left in force a lower court order blocking the start of construction on TC Energy Corp’s Keystone XL pipeline, while a district court ordered the shutdown of Dakota Access (although that project scored temporary relief last week).

In the case of High Plains, which delivers oil to Marathon Petroleum Corp.’s 74,000 barrel-a-day Mandan refinery, the U.S. Interior Department’s Bureau of Indian Affairs ordered it shut after determining the pipeline was trespassing on Native American land. The ruling also found the company responsible for $187 million in damages and gave it 30 days to appeal.

Rights of Way

The legal right-of-way for High Plains to cross some 90 acres of the Fort Berthold Reservation in North Dakota was first initiated in 1953 and renewed every 20 years — in 1973 and again 1993 — according to court documents.