OCETI SAKOWIN CAMPGROUND, N.D. Federal authorities have halted construction of the controversial Dakota Access Pipeline amid growing protests that were expected to draw some 2,000 U.S. military veterans .

The Department of the Army has denied the final easement required for the $3.8 billion project to cross under Lake Oahe in North Dakota, it announced Sunday. Instead, it will conduct an Environmental Impact Statement to examine the impacts and explore alternative routes, it said.

Although we have had continuing discussion and exchanges of new information with Standing Rock Sioux and Dakota Access, its clear that theres more work to do, Jo-Ellen Darcy, the Armys assistant secretary for civil works, said in a statement. The best way to complete that work responsibly and expeditiously is to explore alternative routes for the pipeline crossing.