The Tribe files a lawsuit in federal district court in Washington, D.C., where it was assigned to U.S. District Judge James E. Boasberg.

The Tribe asks the Court for a preliminary injunction since the pipeline is already under construction and would be finished before the case could be formally decided.

Judge Boasberg holds a hearing on the motion in Washington, D.C. Over 500 people participated in an action outside the federal courthouse in support of the Tribe. The Judge indicated that he would rule in roughly two weeks.

While the parties are awaiting the Court’s decision, Dakota Access bulldozed an area of the pipeline corridor filled with Tribal sacred sites and burials that had been identified to the Court just the previous day. Demonstrators trying to prevent the destruction of the sacred site were pepper sprayed and attacked by guard dogs (as documented by Amy Goodman and her Democracy Now camera crew.) On Sept. 4, the Tribe files an emergency motion for a temporary restraining order to block the construction until a decision is reached on the injunction motion.

Judge Boasberg holds a hearing on the emergency motion for a temporary restraining order. The Judge issues a temporary restraining order for the pipeline corridor nearest the Missouri River but declines to halt construction on the portion of the pipeline route that had recently been identified as sacred tribal burial ground.

The Court denies the Tribe’s motion for a preliminary injunction. Minutes later, three federal agencies—The Department of Justice, Department of the Army and Department of the Interior—issue a joint statement announcing that the federal agencies will halt any additional permitting and reconsider its past permits of the project. The statement states that while it appreciates the Court’s review, the government believes that the Tribe has raised some important issues worthy of additional consideration. It also called for a national review of the government’s approach to Tribal consultation for major fossil fuel projects.

After filing an appeal of the District Court’s decision with the D.C. Circuit Court of Appeals, the Tribe files a request for an injunction pending appeal. The motion asks the Court to make the Government’s request for a voluntary pause on construction within 20 miles of Lake Oahe an enforceable requirement while the appeal process goes forward.

The Court issues an order issuing an “administrative injunction … to give the court sufficient opportunity to consider the emergency motion for injunction pending appeal.” The court directed “that Dakota Access LLC be enjoined pending further order of the court from construction of the Dakota Access Pipeline for 20 miles on both sides of the Missouri River at Lake Oahe.”

Oral arguments on the emergency motion for injunction are held at the Court of Appeals for the D.C. Circuit. A ruling was not issued, keeping the temporary halt to construction in place until the Court issues a decision.

The D.C. Circuit issues a ruling denying the tribe’s request for an injunction pending appeal but emphasizes that it hoped that the “spirit of Section 106 [of the National Historic Preservation Act] may yet prevail” as the Court did not have the last word, and decisions still need to be made at the permit crossing at Lake Oahe. Both the appeal and the district court litigation will proceed, but the injunction covering work in the pipeline corridor has ceased.

The Department of Justice, Department of the Army and Department of the Interior issue a joint statement following the court order which says in part: “The Army continues to review issues raised by the Standing Rock Sioux Tribe and other Tribal nations and their members and hopes to conclude its ongoing review soon. In the interim, the Army will not authorize constructing the Dakota Access Pipeline on Corps land bordering or under Lake Oahe. We repeat our request that the pipeline company voluntarily pause all construction activity within 20 miles east or west of Lake Oahe.”

Dakota Access has forcefully rejected the Government’s request for a voluntary pause, and continues to pursue construction ever closer to the Missouri River and the camps of protesters.

The Army Corps conducts a site visit to the area bulldozed over Labor Day to determine whether Dakota Access violated federal law by knowingly damaging a tribal sacred site. Under federal law, if Dakota Access is found to have knowingly damaged a historic or cultural resource with the intent of sidestepping the National Historic Preservation Act, the Corps cannot issue the easement. No determination has been finalized.

As confrontations between Tribal water protectors and an increasingly militarized construction effort heat up, Tribal Chairman Dave Archambault II calls on the Department of Justice to conduct an investigation into heavy-handed police tactics and violations of civil rights.

Following comments from President Obama in an interview on Nov. 1, Tribal Chairman Dave Archambault II issues a statement, saying in part, “While the Army Corps of Engineers is examining this issue we call on the Administration and the Corps to issue an immediate ‘stop work order’ on the Dakota Access Pipeline.” Read the Tribe's full statement.

“Earthjustice is honored to represent the Standing Rock Sioux Tribe in court as it seeks to protect its people’s sacred lands and water from the Dakota Access pipeline,” said Trip Van Noppen, president of Earthjustice, also in response to President Obama's Nov. 1 remarks. “We also want to reiterate the Chairman’s call for a full environmental impact statement. No such careful review has occurred to date. Considering all that’s at stake, that’s simply unacceptable.” Read Earthjustice's full statement.

An independent expert hired by the Standing Rock Sioux Tribe (Richard Kuprewicz of Accufacts, Inc., a consulting firm that advises government agencies and industry about pipelines) finds that the government’s environmental assessment of the Dakota Access pipeline’s environmental impact was inadequate. In light of Kuprewicz’s report and the deficiencies contained in the environmental assessment, Tribe Chairman Archambault II asked for the government to reconsider its early decisions and disallow the easement for the pipeline crossing. Read the letter to Assistant Secretary Jo-Ellen Darcy. Read the Accufacts report. Read the news release.

The Department of Justice announces in federal court that it will be announcing the next steps on a 'path forward' for the Dakota Access Pipeline crossing at Lake Oahe. Read the Tribe's statement.

The U.S. Army Corp of Engineers announces they are delaying an easement for the Dakota Access Pipeline project until it conducts further environmental review with the Standing Rock Sioux Tribe. “We are encouraged and know that the peaceful prayer and demonstration at Standing Rock have powerfully brought to light the unjust narrative suffered by tribal nations and Native Americans across the country,” says Standing Rock Sioux Tribal Chair David Archambault II.

Energy Transfer Partners, the company behind the Dakota Access Pipeline files a lawsuit charging the U.S. Army Corp of Engineers has no right to delay easement to pipeline construction.

The Standing Rock Sioux Tribe issues a statement calling on President Obama to deny easement, investigate pipeline safety and protect tribal sovereignty. Read the Tribe's statement.

Federal officials announce that a decision had been made to close access to the entire area north of the Cannonball River including the Standing Rock protest campsite at Oceti Sakowin. They said the decision was made because of public safety concerns and that a 'free speech zone' to the south of Cannonball River would be created. Anyone on the closed land after Dec. 5 could be charged with trespassing. Read the Tribe's statement.

The Water Protector Legal Collective, an initiative of the National Lawyers Guild, files a lawsuit in U.S. District Court against Morton County, Morton County Sheriff Kyle Kirschmeier, and other law enforcement agencies for using excessive force against peaceful protesters near the Standing Rock protest camp on the night of November 20. More details. (Earthjustice, representing the Standing Rock Sioux Tribe in litigation against the U.S. Army Corps of Engineers, is not involved in this class action lawsuit.)

Standing Rock Sioux Tribe Chairman Dave Archambault II responds to Gov. Dalrymple's Nov. 28 executive order calling for mandatory evacuation of all campers located on U.S. Army Corps of Engineers lands (also known as the Oceti Sakowin camp), saying, in part, "If the true concern is for public safety than the Governor should clear the blockade and the county law enforcement should cease all use of flash grenades, high-pressure water cannons in freezing temperatures, dog kennels for temporary human jails, and any harmful weaponry against human beings." Read the Tribe's full statement.

The Standing Rock Sioux Tribe, the Cheyenne River Sioux Tribe and the Yankton Sioux Tribe ask the Inter-American Commission on Human Rights to stop the violence against water protectors at Standing Rock. An official petition has been submitted to the IACHR.

The Dakota Access Corporation is not granted the easement needed for construction under Lake Oahe. The U.S. Army Corps of Engineers moves to prepare an Environmental Impact Statement for alternative routes. Read more.

DAPL files a motion for summary judgment. Read the legal document.

Tribal representatives testify at a hearing by the Inter-American Commission on Human Rights. The hearing examined the impact of extractive industries and projects on the human rights of indigenous peoples, focusing on the Dakota Access Pipeline and the Standing Rock Sioux Tribe, the Cheyenne River Sioux Tribe, and the Yankton Sioux Tribe.

The Standing Rock Sioux Tribe files a motion with the U.S. District Court in Washington, D.C., asking District Judge James Boasberg to throw out Dakota Access’s lawsuit against the Army Corps of Engineers. The Department of Justice, which represents the Corps, files a similar motion.

The scoping notice soliciting public comment on the Environmental Impact Statement process for the Dakota Access Pipeline is published in the Federal Register. The notice opens the public scoping phase and invites interested parties to identify potential issues, concerns, and reasonable alternatives that should be considered in an EIS. Comments from the public are being requested through Feb. 20.

President Donald Trump takes executive action towards an approval of an easement for the Dakota Access Pipeline, risking contaminating tribal and American water supplies while disregarding treaty rights. “The existing pipeline route risks infringing on our treaty rights, contaminating our water and the water of 17 million Americans downstream,” said Dave Archambault II, chairman of the Standing Rock Sioux Tribe. “We are not opposed to energy independence. We are opposed to reckless and politically motivated development projects, like DAPL, that ignore our treaty rights and risk our water. Creating a second Flint does not make America great again.” Read full statement from the Standing Rock Sioux Tribe. Read statement from Earthjustice.

Senators Cantwell, Tester and Udall send a letter to the White House expressing their concern about the Presidential Memorandum issued January 24 and reports that the Army Corps of Engineers intends to grant a final easement allowing construction of the Dakota Access Pipeline without appropriate consultation with the Standing Rock Sioux Tribe and due process. Read the letter.

The Army Corps of Engineers notifies Congress that—within the next 24 hours—it will issue an easement to allow the Dakota Access Pipeline to cross under Lake Oahe in North Dakota near the Standing Rock Sioux Tribe reservation. Read the EIS termination. Read the Army memorandum.

The easement is issued.

The Standing Rock Sioux Tribe files a motion for summary judgment, asking the Court to overturn recent Army Corps of Engineers permits of the pipeline issued without environmental review or consideration of treaty rights. The lawsuit challenges the Corps’ hasty and unexplained departure from its previous decision, and explains how the Corps ignored the Tribe’s treaty rights and seeks to destroy culturally significant and sacred sites. It also explains how the Corps violated federal statutes requiring close environmental analysis of significant and controversial agency actions. Read the legal document.

North Dakota Gov. Burgum issues an emergency evacuation order of the Oceti Sakowin camp, ordering that the site be vacated by 2:00pm local time on Feb. 22. In a statement on Feb. 7, Standing Rock Chairman Archambault II had asked supporters to “please respect our people and do not come to Standing Rock and instead exercise your First Amendment rights and take this fight to your respective state capitols, to your members of Congress, and to Washington, D.C.”

The Standing Rock Sioux Tribe issues Setting The Record Straight, documenting engagement on the Dakota Access pipeline.

A buried memo from Interior Department's top lawyer surfaces in legal filings. The 35-page formal legal opinion, dated Dec. 4, found that the existing environmental assessment for the Dakota Access pipeline suffered from fatal flaws. The Trump administration quietly suspended the opinion as it prepared to approve the pipeline. Of the Trump administration's attempts to bury the memo, Earthjustice attorney Jan Hasselman said, "The Standing Rock Sioux deserve better. That's why we have courts." Read details.

The Standing Rock Sioux Tribe applauds BNP Paribas’ decision to divest from the Dakota Access Pipeline. “As corporate greed continues to fuel dirty energy projects on our land, it is heartening to see that some banks recognize the imminent harm to our people posed by DAPL, and are taking actions accordingly,” said Dave Archambault, Chairman of the Standing Rock Sioux Tribe. “We appreciate BNP Paribas, ING and DNB leadership and their advanced understanding and respect of tribal sovereignty and Indigenous Peoples’ rights.”

The local South Dakota outlet Aberdeen News reports that a leak occurred in the not-yet completed Dakota Access pipeline on April 6. “Our lawsuit challenging this dangerous project is ongoing, and it’s more important than ever for the court to step in and halt additional accidents before they happen—not just for the Standing Rock Sioux Tribe and our resources, but for the 17 million people whose drinking water is at risk,” said Standing Rock Sioux Tribe Chairman Dave Archambault II.

The Standing Rock Sioux Tribe wins a significant victory, when Judge James Boasberg rules that the federal permits authorizing the pipeline to cross the Missouri River just upstream of the Standing Rock reservation, which were hastily issued by the Trump administration just days after the inauguration, violated the law in certain critical respects. The Court did not determine whether pipeline operations should be shut off, requesting additional briefing on the subject and a status conference for the following week. Read the court opinion.

The U.S. District Court for the District of Columbia issues an opinion on the pipeline operations during the new environmental review process. Read the legal document.

The U.S. Army Corps of Engineers issues a brief decision, affirming its original decision to issue a construction permit for the Dakota Access Pipeline. Read the legal analysis.

The Standing Rock Sioux Tribe renews their lawsuit against the U.S. Army Corps of Engineers, challenging its recently completed review of the pipeline’s impacts and filing a supplemental complaint in its existing case. Read the legal analysis.

The Standing Rock Sioux Tribe’s continuing legal battle against the Dakota Access Pipeline advanced with a motion for summary judgment filed in U.S. District Court in Washington, D.C.

D.C. District Court granted a request by the Standing Rock Sioux Tribe to strike down federal permits for the controversial Dakota Access Pipeline. The Court found the U.S. Army Corps of Engineers violated the National Environmental Policy Act when it affirmed federal permits for the pipeline originally issued in 2016. Specifically, the Court found significant unresolved concerns about the potential impacts of oil spills and the likelihood that one could take place.

The Corps and Dakota Access filed briefs with the Court asking it to allow the pipeline to continue to operate while a full EIS is prepared, as required by the Court’s recent decision. The Corps claims to be able to finish an EIS by mid-2021, already signaling that it will not take the process seriously. DAPL breathtakingly calls DAPL the safest pipeline in the world, relying on secretive information that it has shielded from any public scrutiny. These briefs were supported by no less than six “amicus” (friend of the court) briefs representing oil companies, industry groups, and the state of North Dakota.

The Standing Rock Sioux Tribe files its legal brief asking the Court to shut down the Dakota Access pipeline while an Environmental Impact Statement is performed. The brief explained how shutting down the pipeline would have limited impacts in light of the collapse in North Dakota oil production, and that leaving it in place continues a pattern of government-sponsored trauma dating back two centuries.

The D.C. District Court orders the owners of the Dakota Access Pipeline to halt operations while the government conducts a full-fledged analysis examining the risk DAPL poses to the Standing Rock Sioux Tribe. The shutdown will remain in place pending completion of a full environmental review, which normally takes several years, and the issuance of new permits. It may be up to a new administration to make final permitting decisions.