While President Trump has declared he would reopen the Keystone XL pipeline “immediately,” the reality of federal and state permitting means such a project would require months—or more likely years—of complex regulatory approvals, even with presidential support. The Trump administration has already begun working with Canada on permits for a potential partial Keystone XL revival as of March 2026, but nearly every permit along the original route has expired since the project was cancelled in 2021, forcing any new effort to restart from scratch. The comparison is stark: Obama blocked the original Keystone XL in 2015 after a lengthy permitting process, and Trump initially revived it through a presidential permit in 2017, only to see Biden cancel it again in 2021—each transition required a full permit review, demonstrating how dependent these projects are on regulatory processes rather than executive will alone. The central hurdle is that “immediately” collides with reality: a pipeline crossing international borders and state lines cannot bypass environmental reviews, public comment periods, and agency approvals that are built into federal law.
What the Trump administration can control—the presidential permit for crossing the Canada-U.S. border—represents only one piece of a much larger puzzle. Beyond that, the Army Corps of Engineers must approve water crossings, the Interior Department must conduct environmental assessments, and Montana, South Dakota, and Nebraska must grant state permits. Even if all federal approvals moved at record speed, state-level reviews alone could add substantial time, and the original project’s developer, TC Energy (now South Bow Corp.), has publicly stated it has “moved on from Keystone XL,” creating an additional complication: there may be no willing builder to reconstruct portions of the pipeline that were dismantled after cancellation.
Table of Contents
- What Permits Must Be Approved Before Keystone XL Could Begin Construction?
- Why Have Existing Permits Expired, and What Does This Mean for Revival?
- What State-Level Approvals Are Required, and Where Could They Create Delays?
- Could the Trump Administration Simply Bypass State Requirements Through Executive Action?
- What Environmental and Water Rights Issues Could Slow or Block Approval?
- What Is the Bridger Pipeline Alternative, and How Does It Compare to Keystone XL?
- What Does the Current Status Tell Us About Realistic Timelines for a Keystone XL Decision?
- Conclusion
What Permits Must Be Approved Before Keystone XL Could Begin Construction?
The presidential permit stands as the most visible obstacle the trump administration can directly control, yet it represents just the first hurdle in a multi-layer approval system. A presidential permit is required for any energy infrastructure crossing the U.S.-Canada border, and while the Trump administration has already signaled its intent to support this, obtaining the permit legally requires the State Department to conduct a National Interest Determination—a review process that, while faster under a sympathetic administration, still takes months. Beyond the presidential permit, the Army Corps of Engineers must issue permits for any pipeline sections that cross waterways, including rivers and wetlands in Montana, South Dakota, and Nebraska. The Interior Department’s Bureau of Land Management (BLM) must also issue permits for pipeline segments crossing federal lands, a process that now includes mandatory public comment periods. The additional federal requirements add complexity that cannot be compressed into weeks.
The National Environmental Policy Act (NEPA) requires federal agencies to conduct and publish environmental impact assessments before major projects can proceed, and while an expedited review might compress this timeline, it cannot eliminate it entirely. A comparison to the original Keystone XL permitting process illustrates the point: even with bipartisan support in Congress and White House backing, the original project took years to move through NEPA reviews and agency approvals. The BLM’s current review of the similar Bridger Pipeline project demonstrates that even parallel efforts face months-long public comment periods and environmental assessments, with the agency seeking input on routing through Montana and Wyoming. This suggests that any Keystone revival would face comparable timelines, regardless of political will in Washington.
Why Have Existing Permits Expired, and What Does This Mean for Revival?
When the Biden administration cancelled Keystone XL in 2021, it invalidated the project’s permits, but that action had a secondary consequence: virtually all permits along the original route have now expired, forcing any new project to restart the permitting process entirely from the beginning. This is not a minor bureaucratic issue—it means that the years of environmental studies and agency approvals that occurred under Trump would need to be repeated or at least substantially revisited. Federal permits are typically valid for a set number of years, and after cancellation, companies either maintain and renew them (which TC energy did not do after Biden’s decision) or they lapse. The expiration creates a hard reset: no previous work can be cited as conclusive, and new environmental conditions, regulatory standards, or public concerns can force reviews to cover ground already covered years earlier. The practical implication is severe: TC Energy walked away from the original Keystone XL entirely after Biden’s 2021 cancellation, writing down billions in sunk costs.
The company has since “moved on,” indicating it does not intend to pursue the original project again. This means that even if Trump’s administration expedites federal approvals, there is no certain builder ready to construct the pipeline or to undertake the regulatory burden. The infrastructure that was already built before cancellation—sections in Alberta, Montana, South Dakota, and Nebraska—has been partially dismantled, and reconstructing it would require additional environmental and engineering reviews. A warning here is essential: executive action on permitting means little if the private developer lacks the financial or strategic incentive to build. Trump can clear the regulatory path, but he cannot compel TC Energy to rebuild a project that management has already abandoned.
What State-Level Approvals Are Required, and Where Could They Create Delays?
Beyond federal permits, the pipeline would need approval from the states it crosses—Montana, South Dakota, and Nebraska—each of which has its own regulatory bodies and approval processes. Montana, for example, requires state permits for pipelines crossing its borders and for operations within the state, a process overseen by the Montana Department of Environmental Quality and the Public Service Commission. South Dakota and Nebraska have comparable requirements. Unlike federal permitting, which a president can theoretically accelerate through agency leadership, state permitting operates under state law and state political dynamics that White House pressure cannot directly override. A governor sympathetic to the project can streamline reviews, but state legislatures, local communities, and environmental commissions have formal roles in these decisions.
The Bridger Pipeline proposal illustrates the current state-level environment. This 647-mile alternative route from Canada through Montana to Wyoming, with an initial capacity of 550,000 barrels per day and a $2 billion estimated cost, is moving through the permitting process but still requires extensive state and local reviews. Montana has seen significant environmental and agricultural opposition to pipeline projects that cross productive farmland and ranches, concerns that persist regardless of federal political leadership. Some landowners along potential routes have used state processes to slow or block projects entirely, and state environmental standards in Montana are in some cases stricter than federal minimums. This means that a Keystone revival would face not just regulatory approval but potential local resistance amplified through state-level processes, particularly in counties where the pipeline would cross private property or sensitive lands.
Could the Trump Administration Simply Bypass State Requirements Through Executive Action?
A common misconception is that Trump’s control over federal permitting translates to control over state permitting, but constitutional law and federalism prevent this. States retain authority over land use, environmental protection, and infrastructure siting within their borders, and the federal government cannot compel states to issue permits or override state regulatory decisions through executive action alone. What the Trump administration can do is pressure state officials politically, coordinate with governors who support the project, or potentially argue that a federal project overrides state concerns under theories of federal preemption—but such legal arguments are contested and have uncertain outcomes. For a private pipeline project like Keystone XL, federal authority to override state permitting is even more limited. The practical reality is that permitting timelines depend on state-level cooperation.
If Montana, South Dakota, and Nebraska have sympathetic governors and legislatures, the process could move faster. If they do not—or if state courts become involved due to challenges from environmental groups or landowners—timelines can extend indefinitely. A comparison illustrates the point: the Dakota Access Pipeline faced years of legal challenges and state-level opposition even with federal backing, ultimately requiring the Army Corps of Engineers to conduct an additional environmental assessment after construction had begun. The Keystone XL situation could follow a similar path, where federal expedited permitting gets followed by state-level lawsuits or administrative challenges that reach state courts. The Trump administration cannot bypass these processes, only participate in them and hope for favorable state-level cooperation.
What Environmental and Water Rights Issues Could Slow or Block Approval?
Environmental assessments required by federal law focus heavily on water impacts, endangered species, greenhouse gas emissions, and cumulative effects of infrastructure. The Keystone pipeline would cross the Missouri River and various tributaries, triggering reviews of impacts on water quality, aquatic life, and tribal water rights. Native American tribes with treaty rights to water in the region—particularly the Sioux tribes in South Dakota—have historically fought pipeline projects and can use federal consultation requirements and litigation to challenge approvals. The National Environmental Policy Act requires federal agencies to consider these concerns, and even a sympathetic administration cannot simply dismiss environmental impacts; it can only determine that benefits outweigh costs.
A critical warning: environmental reviews can uncover new concerns or changed conditions that delay projects substantially. When the original Keystone XL went through permitting under Trump, updates to endangered species lists and new scientific data on climate impacts required additional analysis. If a new Keystone XL review were to be conducted in 2026, updated climate science, new data on water table impacts, or newly listed endangered species could trigger expanded environmental assessments. The State Department’s National Interest Determination process, while it can expedite the presidential permit, cannot avoid the underlying requirement that federal agencies base decisions on current environmental evidence. A pipeline that crosses nine counties in Montana alone will face environmental concerns in each location, and cumulative impacts must be assessed per federal law. Even a Trump administration committed to the project cannot avoid these reviews; it can only try to move them faster.
What Is the Bridger Pipeline Alternative, and How Does It Compare to Keystone XL?
As the original Keystone XL faces hurdles, a new proposal—the Bridger Pipeline—is advancing through permitting as a potential alternative. The Bridger Pipeline would run 647 miles from the Canada-Montana border through Wyoming to the Guernsey crude hub, with an initial capacity of 550,000 barrels per day and a potential future capacity exceeding 1 million barrels per day. The project is estimated to cost $2 billion and is being reviewed by the BLM, which opened public comment periods in 2026. Unlike Keystone XL, which was partially constructed before cancellation, the Bridger Pipeline is entirely new infrastructure, meaning it requires permitting from scratch but avoids the complication of reconstructing dismantled segments.
The comparison reveals a strategy shift: rather than resurrecting the exact original Keystone XL route, proponents are pursuing a similar project through a potentially less controversial path. The Bridger route through Wyoming might avoid some of the most vocal opposition that Keystone XL faced in South Dakota and Nebraska, though Montana landowners and environmental groups are already engaged in the review process. For the Trump administration, supporting Bridger in parallel with pushing Keystone XL revival provides a backup option: if Keystone XL permitting stalls, Bridger could be the project that actually gets built. However, both cannot proceed simultaneously—the market for Canadian crude imports into the U.S. is not unlimited—and a competition between them could delay both projects as investors and regulators determine which is more viable.
What Does the Current Status Tell Us About Realistic Timelines for a Keystone XL Decision?
As of March 2026, the Trump administration is actively working with Canada on permits for a potential partial Keystone XL revival, but this language—”working with Canada” and “potential”—signals that no final decision has been made and no permitting has yet formally begun. The government is likely still assessing whether to pursue the original Keystone XL route, a modified version, or to focus on alternative projects like Bridger. This assessment phase typically lasts months and involves consultation with state officials, the private sector, and federal agencies. Even after decisions are made, the actual permitting process—environmental reviews, public comment periods, and agency approvals—could easily extend 18 months to three years, depending on political and legal challenges.
The historical precedent is instructive: Trump’s 2017 Keystone XL permit approval followed several months of review, but that decision was itself contested in court for years thereafter, and the project ultimately depended on continuous executive action to survive legal challenges. A new revival would likely face similar litigation, with environmental groups and tribes challenging any approval in federal court. Even with executive support and fast-tracked federal permitting, state processes could add 12 to 24 months. The realistic assessment is that “immediately” means something very different in permitting timelines than in political rhetoric. A pipeline that could realistically begin construction in 2027 or 2028 would represent aggressive timelines; one beginning before 2027 would require extraordinary political and legal luck, or an alternative route like Bridger that faces less opposition.
Conclusion
President Trump’s promise to reopen Keystone XL “immediately” reflects his authority over federal permitting and his administration’s willingness to fast-track approvals, but it collides with a multi-layered legal reality that no executive can entirely bypass. The presidential permit, the first and most visible hurdle, can be issued quickly under a sympathetic administration, but that represents perhaps 20 percent of the actual approvals required. The Army Corps of Engineers, Interior Department, and three state governments must also grant permits, each with mandatory environmental reviews, public comment periods, and legal requirements. Expired permits along the original route mean starting from scratch, not simply reviving old approvals, and the original developer, TC Energy, has walked away, leaving unclear who would actually build the reconstructed sections.
What the Trump administration can realistically deliver is a cleared federal pathway and political momentum, but permitting timelines will be measured in months to years, not weeks. State-level resistance, environmental reviews, and litigation by tribes and environmental groups remain outside executive control, even for a sympathetic administration. The parallel pursuit of the Bridger Pipeline suggests that even proponents recognize Keystone XL revival faces obstacles, and Bridger might be the project that actually gets built if it navigates state approvals more smoothly. For anyone tracking this issue—whether as a potential investor, affected landowner, or policy observer—the key question is not whether Trump will attempt to revive Keystone XL, but whether the underlying permitting architecture will allow any such project to move from concept to construction in the timeframe suggested by “immediately.”.