According to Reuters, a federal judge in Montana halted construction of the Keystone XL oil pipeline on Thursday on the grounds that the U.S. government did not complete a full analysis of the environmental impact of the TransCanada project.The ruling deals a major setback for TransCanada Corp and could possibly delay the construction of the $8 billion pipeline. The ruling is a victory for environmentalists, tribal groups and ranchers who have spent more than a decade fighting against construction of the pipeline.