Keystone XL

"I wish I could say I was shocked, but a major spill from the Keystone pipeline is exactly what multiple experts predicted would happen," said a Greenpeace USA senior research specialist.

Nebraska's Public Service Commission cleared the way for the controversial project on Monday. Here's everything you need to know.

Trump on Monday false claimed during remarks to business leaders in Tokyo that construction for the controversial pipeline is underway, even though the project hasn't found buyers yet.

Over the past year oil companies have discovered volumes on Alaska's North Slope totaling as much as five billion barrels or more of recoverable oil.

The pipeline had been blocked by Obama, who said it would do nothing to reduce fuel prices for U.S. motorists and would contribute to emissions linked to global warming.

The move would mark the beginning of a process that could be lengthy. Approvals are needed from state regulators, and the project could face legal challenges.

Protesters were set to gather in a number of U.S. cities on Wednesday, a day after the U.S. Army said in a legal filing it planned to cancel an environmental study and grant the final easement needed to complete the Dakota pipeline.

Paul Ryan and Donald Trump used to feud. They don't any longer.

While oil producers in Canada and North Dakota are expected to benefit from a quicker route for crude oil to U.S. Gulf Coast refiners, a revival of the projects would mark a bitter defeat for Native American tribes and climate activists.

With a global climate change summit looming, so are fights over Obama proposals.

The project, he said, would have done less than promised for the U.S. economy, and would "undercut" the country's position as a global leader in fighting climate change.

"The pipeline would not make a meaningful long-term contribution to our economy," the president said.

The decision is expected to lead to the project's rejection by the Obama administration.

The president has increasingly signaled the $8 billion pipeline may not be approved.

But all signs seem to suggest it might be on its last legs.

A delay would almost certainly hand the decision for the $8 billion project to a future president.

She called the pipeline a "distraction."

The controversial project now awaits an administration decision on whether to permit or deny it.

The world's third largest oil reservoir may never see the light of day.

The temporary injunction was prompted by a lawsuit from 70 landowners who don't want the pipeline on their property.

A final decision from the President could come as early as February.

The decision approves Transcanada's route through Nebraska, but might open a whole other can of worms for the company

The Nebraska Supreme Court's decision reversed a lower court that had blocked the proposal and cleared the way for a U.S. State Department ruling on the plan.

"It will create jobs for American and Canadian workers, it has the support of the Canadian and American people."

Republicans say that they have a plan to pass it regardless.

President's former press secretary hints that Obama may veto the pipeline.

With all eyes on Keystone, another tar sands pipeline is wending into the U.S., without a permit.

In a 59 to 41 vote, the U.S. Senate narrowly voted to reject the Keystone XL pipeline Tuesday evening after several hours of intense debate.

It appears the pro-pipeline coalition in the Senate may now be one vote short.

Enbridge, the company behind the 2010 Kalamazoo River spill, has found a way to increase its tar sands capacity without a U.S. permit