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Standing Rock Sioux Tribe v. US Army Corps of Engineers
Litigation challenging pipeline approvals, asserting Treaty rights, environmental justice, NEPA violations, and demanding federal review to protect Standing Rock sovereignty.
- Standing Rock Sioux Tribe v. U.S. Army Corps of Engineers is the central federal lawsuit challenging the approvals granted for the Dakota Access Pipeline (DAPL), asserting violations of the Tribe’s Treaty rights, threats to their primary water source at Lake Oahe, failures under the National Environmental Policy Act (NEPA), and systemic environmental injustice. Filed in July 2016, the litigation quickly became the legal backbone of the #NoDAPL movement—an Indigenous-led human rights, Treaty rights, and environmental protection effort that transformed global conversations about energy infrastructure and Indigenous sovereignty.
At the core of the Tribe’s claims is the federal permitting process for the pipeline’s Missouri River crossing at Lake Oahe, less than a half-mile from the Standing Rock Sioux Reservation and directly on unceded Treaty lands of the Oceti Sakowin affirmed in the 1851 and 1868 Fort Laramie Treaties. The location carries profound cultural, historical, and spiritual significance, as well as existential stakes for drinking water, subsistence practices, and the ecological integrity of a region already devastated by federal dam projects. The pipeline’s siting at Lake Oahe echoes the trauma of the 1959 Pick-Sloan Plan—described by historian Vine Deloria, Jr. as “without a doubt, the single most destructive act ever perpetrated on any tribe by the United States”—which forcibly displaced over 900 Indigenous families and flooded more than 55,000 acres of forest, wetlands, and traditional lands to construct the Oahe Dam.
Despite this history, the U.S. Army Corps of Engineers approved DAPL’s Missouri River crossing through a truncated and piecemeal review that the Tribe repeatedly warned failed to consider impacts on their Treaty rights, cultural resources, or the risk to their sole water supply. Early federal agency comments raised the same issues: the Environmental Protection Agency, Department of the Interior, and Advisory Council on Historic Preservation all urged USACE to conduct a full Environmental Impact Statement (EIS) and to meaningfully consult with the Tribe. The Corps proceeded instead with a limited Environmental Assessment (EA) that relied heavily on assumptions and industry assurances, minimized the significance of potential spills and drilling impacts, and falsely claimed Tribal consent or lack of concern.
In February and March 2016, the Tribe’s Tribal Historic Preservation Officer, along with cultural experts and historians, urgently notified USACE and DAPL of sacred sites, burial grounds, stone features, and ceremonial locations along and near the pipeline route—including those later documented extensively in the 2016 Mentz Declaration. Yet these warnings were ignored or mischaracterized in the federal record. On September 3, 2016, less than 24 hours after Tribal filings detailed the precise locations of previously undocumented sacred sites, DAPL construction crews bulldozed the area, destroying cultural resources that had stood for generations. The Tribe immediately sought an emergency restraining order, arguing the destruction was deliberate and conducted to preempt legal protection.
Throughout the fall and winter of 2016, the Tribe continued to press the Corps for proper environmental review. In December 2016, after months of Indigenous-led mobilization and global support, the Obama administration announced that DAPL could not proceed at Lake Oahe without a full EIS. Weeks later, the incoming administration reversed course, directing USACE to fast-track the easement without completing the EIS or adequately responding to Treaty-based concerns.
The Tribe amended its lawsuit under the Administrative Procedure Act (APA), challenging the Corps’ reliance on an incomplete and insufficient EA, failures to analyze spill risk, impacts to reserved rights to hunt, fish, and drink clean water, environmental justice implications, and the agency’s disregard of scientific evidence about pipeline failure rates and Horizontal Directional Drilling risks. They also challenged the agency’s refusal to consider the disproportionate burden placed on a Tribal Nation after the Bismarck route—originally rejected due to risks to a largely non-Indigenous population—was shifted to unceded Sioux land.
In 2020, after years of litigation and extensive evidentiary review, the U.S. District Court for the District of Columbia ruled that the Corps had violated NEPA by failing to adequately consider spill risks, environmental justice implications, and controversies requiring a full EIS. The court vacated the easement and ordered a comprehensive EIS—the very outcome the Tribe had sought since 2016. The D.C. Circuit affirmed that the pipeline was operating without a valid federal easement, underscoring the seriousness of the Corps’ deficiencies.
2024–2026: Renewed Litigation and Ongoing Appeals
In 2024, on Indigenous Peoples’ Day, the Tribe again filed suit arguing that federal action had been unlawfully withheld and unreasonably delayed, as the EIS remained incomplete years after the court had ordered it. The Tribe asserted that the continued operation of DAPL without a valid easement—and without a final EIS—constituted an ongoing violation of federal law and placed the Tribe at continuing risk.
In March 2025, Judge James Boasberg of the U.S. District Court for the District of Columbia rejected the Tribe’s claims, finding no basis to compel immediate federal action despite the absence of a completed EIS or valid easement. The Tribe appealed this decision.
On November 5, 2026, the Standing Rock Sioux Tribe filed its appeal in the D.C. Circuit Court of Appeals, continuing to challenge the Corps’ failure to complete the EIS and the ongoing illegal operation of the pipeline. Jeffrey Parsons, Peter Capossela, and Natali Segovia of the Water Protector Legal Collective serve as counsel for the Tribe in the 2026 appeal.
Present Day
Today, Standing Rock Sioux Tribe v. USACE remains a defining legal struggle over the United States’ obligations to honor Treaty rights, respect Tribal sovereignty, and uphold statutory protections designed to ensure environmental safety and public participation. The litigation continues to challenge not only DAPL’s unlawful operation, but the broader structure of federal decision-making that has repeatedly sacrificed Indigenous land, culture, and safety for the benefit of extractive industries. The case stands as a critical precedent for Indigenous environmental justice movements worldwide and as a reminder that protecting water, land, and Treaty rights requires sustained vigilance against both corporate and governmental violations.
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