
As one of his last moves in office, on December 4th, former President Obama halted completion of the pipeline by revoking permission for Energy Transfer Partners, the pipeline owner, to use Federal land there pending an Army Corps of Engineers assessment.
Upon assuming office, President Trump almost immediately reversed this and allowed construction of the $3.8 billion pipeline to continue. Oil is expected to flow through the pipeline by April.
This development is a huge boon to oil and gas producers in North Dakota and will greatly reduce the cost of bringing their oil to market, as shipping crude through pipelines is both safer and cheaper than by rail.
In-depth discussion on the pipeline is found here.