Though it has rarely surged to the top of the news during this hectic campaign season, the controversy surrounding the Dakota Access Pipeline is likely to intensify this week after Federal officials on Sunday announced that they would not approve permits for its construction beneath a dammed section of the Missouri River that Native American tribes say sits near sacred burial sites.

The decision comes after months of sometimes violent demonstrations, and just as a new administration – one favoring the pipeline – takes office next year. Now, the U.S. Army Corps of Engineers likely will stall the project with hearings, impact statements, and detailed studies of alternative routes.

Here are some crucial facts about the issues involved in the debate:

What is the Dakota Access Pipeline?

A $3.7 billion project designed to transport 470,000 barrels of oil a day through four states, the 1,172-mile Dakota Access Pipeline passes through the vast, oil-rich Bakken Shale area of North Dakota, where there’s an estimated 7.4 billion barrels of undiscovered oil. The oil will be shipped to markets and refineries in the Midwest, East Coast and Gulf Coast regions. This way, project developer Texas-based Energy Transfer Partners says, the United States can continue its evolution as an oil power, rather than relying on imports from unstable regions of the world.

The Pipeline Would Create Jobs, Jobs, Jobs

There is no doubt that the pipeline would be an economic boon to the United States, especially to the currently depressed oil industry, bringing an estimated $156 million in sales and income taxes to state and local governments as well as add 8,000 to 12,000 construction jobs, according to Energy Transfer Partners.

Who are the Protesters?

Though environmentalists have mustered many arguments against the pipeline, the main opponent to its construction has been the Standing Rock Sioux tribe. They sued the US Army Corps of Engineers after the pipeline was granted final permits in July. In addition to threatening their economic and environmental interests, the tribe says the project will cut through land that is sacred. It will “destroy our burial sites, prayer sites and culturally significant artifacts,” their leaders said in a recent statement. They add that says 38 miles of the pipeline cuts through territory that still belongs to Native Americans, based on a 1851 treaty signed at Fort Laramie in Wyoming.

The tribe has been backed by a virtual Who’s Who of Hollywood A-list celebrities. They have set up teepee and tent camps on land owned by Energy Transfer Partners to slow the progress of construction and have threatened to block the highway. Celebrities and public figures like actor Shailene Woodley, actor Mark Ruffalo and civil rights activist Jesse Jackson have traveled to North Dakota. Protesters vow to remain through winter, even though the average low temperature in the state falls to 0 F (-17.8 C).

The Environmental Arguments Against the Pipeline

Pipeline architects say it provides a much safer, more environmentally friendly way of moving crude oil, compared to other modes of transportation like rail or trucks. They point to recent incidents like a 2013 disaster in Quebec, where a train carrying crude oil destroyed downtown Lac-Megnatic when it derailed. But environmentalists say that the Dakota Pipeline doesn’t spur the country’s move away from crude oil toward alternative and renewable sources of energy.

Opponents also worry about what the pipeline, which would go under the Missouri River, could do to the water supply if it ruptured. The Pipeline and Hazardous Materials Safety Administration (PHMSA) has reported more than 3,300 incidents of leaks and ruptures at oil and gas pipelines since 2010.

President-elect Trump Supports the Pipeline

Supporters of the pipeline — which include President-elect Donald Trump as well as state and local government leaders — emphasize the economic benefits to a distressed region and industry. The protestors on the ground have only aggravated the situation, they say. North Dakota Governor Jack Dalrymple has called in the National Guard as well as an army of other police officials. Hundreds have been arrested, even as construction on the pipeline has continued. Trump ”intends to cut the bureaucratic red tape put in place by the Obama administration that has prevented our country from diversifying our energy portfolio,” according to a Trump transition memo recently reported in the Associated Press.

Wasn’t There Another Pipeline in the News Recently?

You’re thinking of the Keystone XL Pipeline. After months of debate, President Obama eventually rejected that project, which was seen by some environmentalists as a litmus test for public officials to show their commitment to addressing climate change. But there’s one big difference. The Keystone crossed into Canada, making it an international issue. That gave authority over its final approval to the State Department. The federal government has the authority over the Dakota Access Pipeline because it crosses interstate waterways. President Obama faces a much more difficult task in trying to stop this pipeline, especially since his elected successor, likely backed by most Republican lawmakers, supports it.