The Standing Rock Sioux Nation is vowing a legal challenge and more after the US Army Corps of Engineers informed the US Congress that it will grant permission to complete the controversial Dakota Access Pipeline.

"The granting of an easement, without any environmental review or tribal consultation, is not the end of this fight.  It is the new beginning.  Expect mass resistance far beyond what Trump has seen so far," said Tom Goldtooth, executive director of the Indigenous Environmental Network.

Indigenous and environmental activists have many objections to the pipeline, but the fact that it is planned to cross under the Missouri River at Lake Oahe, the only point from where the Standing Rock tribe can draw its water.  If the pipeline were to someday rupture, as pipelines sometimes do, the oil would foul the river not just for the reservation, but for cities and agricultural dependents downstream.

The Obama administration decided in early December to delay a final permit that would allow construction under the Missouri River.  But that victory was short-lived, however, as Trump, then president-elect, voiced support for the pipeline.  Then-President Obama also ordered an additional environmental assessment, but that will no longer be conducted with the Corps' decision.

About 400 protesters are maintaining the protest camp during the cold upper plains winter.  The decision made their blood run a little colder.

"All of our hearts are broken," said protest leader Linda Black Elk.  "I'm just going to ask you guys to keep us all in your prayers.  Pray for the water.  Pray for the people.  Pray for the water protectors.  Pray for the tribe."