The protestors of Standing Rock scored a big victory on Sunday when the U.S. Army Corps of Engineers said it would block construction of the Dakota Access Pipeline along its current route near territory held by the Standing Rock Sioux tribe.

Jo-Ellen Darcy, the Army’s Assistant Secretary for Civil Works, said the Army would not permit the easement needed to complete a stretch of the pipeline that would run under Lake Oahe in North Dakota. That section of the pipeline runs close to sacred Sioux burial grounds and has raised concerns about the potential for polluting the tribe’s water supply. The Army Corps of Engineers has authority over the section in question because it also crosses federal lands.

The Standing Rock Sioux’s protest began in the fall and more recently has drawn hundreds of Native Americans and supporters dubbed “water protectors” to encampments near the proposed constitution sites near Cannon Ball, N.D. The issue has been taken up by entertainment industry environmentalists, among many others. On Nov. 27, Jackson Browne and Bonnie Raitt headlined a benefit concert in nearby Fort Yates, N.D., for the Standing Rock cause.

Darcy said the Army would push the private company, Energy Transfer Partners, to find alternative routes for the 1,172-mile pipeline that aims to carry oil from North Dakota to Illinois.

“Although we have had continuing discussion and exchanges of new information with the Standing Rock Sioux and Dakota Access, it’s clear that there’s more work to do,” Darcy said. “The best way to complete that work responsibly and expeditiously is to explore alternate routes for the pipeline crossing.”

Media and entertainment figures who have spoken out about the Dakota Access Pipeline were quick to hail the Army Corps of Engineers’ decision. Some called the move a final hurrah for the Obama administration on the environmental front.