When Section 106 of the National Historic Preservation Act (NHPA) obligations compound with the National Environmental Policy Act (NEPA) and other regulatory hurdles, cumulative coordination burdens become evident. These pressures appear heaviest in long, linear infrastructure projects like transmission lines and pipelines.
This analysis maps the Section 106 review process step by step and identifies where it stalls. Explore the full process through our interactive map, read our complete analysis, or browse through the major process challenges and policy recommendations.
What makes the NHPA uniquely challenging to reform—politically and substantively—is its significance to Native American tribes.
Recurring difficulties in Section 106 review for large linear infrastructure projects emerge from structural tensions between the architecture of the Section 106 process and the operational realities of modern infrastructure deployment.
Sequencing and path dependency: Section 106 consultation and cultural resource identification frequently occur after major project assumptions, routing decisions, and permitting investments have begun to solidify. As infrastructure planning advances, the practical flexibility available to agencies, tribes, and developers may narrow substantially.
Fragmented information and administrative coordination: Section 106 review distributes responsibilities across institutions operating under different timelines, authorities, and informational constraints. Agencies, tribes, applicants, State and Tribal Preservation Officers, consulting parties, and courts may all possess only partial visibility into the broader consultation landscape.
Scale mismatch between historic preservation review and linear infrastructure development: The scale of linear infrastructure projects creates complex coordination demands involving multiple agencies, jurisdictions, tribes, and consulting parties across long geographic corridors. As project scale increases, the review process may experience escalating coordination burdens, administrative strain, and prolonged uncertainty.
Recurring points of failure surface across agencies, administrations, and decades.
NHPA consultation tends to happen late in the NEPA process. The two statutory frameworks are formally integrated. But they serve different purposes, rely on different information, and operate using different procedures. This can result in project assumptions solidifying before cultural resource identification and tribal consultation processes mature, leaving tribes in a reactive posture.
Although the regulations establish timelines under which agencies may proceed following non-response from consulting parties, agencies are often reluctant to exercise that authority in practice. Political sensitivities, litigation risk, and a desire to respect the federal trust responsibility to tribal sovereignty make agencies reluctant to advance projects without tribal participation.
Linear projects can involve dozens of consulting parties, multiple SHPOs and THPOs, overlapping federal jurisdictions, and consultation obligations spanning hundreds of miles.
Agencies may develop alternative procedures for Section 106 compliance, as long as they are consistent with the regulations. But this consistency requirement is challenging for agencies whose statutory authority is poorly matched to the standard Section 106 process.
Large linear infrastructure projects can generate consultation volumes that strain staffing, technical expertise, and review timelines across multiple jurisdictions simultaneously. These capacity pressures may contribute to delays, inconsistent consultation practices, and uneven review outcomes.
Deferred historic- and cultural-resource identification can allow major routing and permitting decisions to solidify before consultation and evaluation are complete, leading to legal and political challenges. The ‘good faith and reasonable effort’ standard for outreach and identification can leave agencies unsure how to proceed. Adequately documenting NHPA compliance for court review is a challenge.
DAPL is a crude oil pipeline from the Bakken fields in North Dakota to Patoka, Illinois, completed in 2017. Federal authority covered only about 37 miles of the route. Tribes argued the government should conduct a Section 106 review on the entire 1,168-mile route. The U.S. Army Corps of Engineers disagreed.
In 2015, the Bureau of Land Management approved SunZia’s route through Arizona’s San Pedro Valley using a phased Section 106 approach that deferred portions of cultural resource identification and treatment planning until after the final permitting decision. By the time tribes formally asserted a valley-wide Traditional Cultural Property and requested rerouting, BLM’s position was that the route was final.
Spanning four states—Wyoming, Colorado, Utah, and Nevada—the project required a large, corridor-wide Section 106 review. This entailed negotiations with four state preservation officers with varying standards and approaches.
The foregoing implementation challenges point toward a coherent set of reforms that would move cultural-resource concerns earlier in the planning process while giving agencies and developers clearer rules for when consultation is complete.
For such projects, Congress should require corridor-level Section 106 screening at the Notice of Intent or pre-application stage. This screening should identify affected tribes, broad areas of cultural concern, and potential routing conflicts before agencies select a preferred route. This should not entail full archaeological surveys or full Section 106 review across every hypothetical corridor.
Congress should create statutory safe harbors for agencies that follow prescribed notice, screening, documentation, confidentiality, and follow-up procedures. Agencies that satisfy those requirements should receive a rebuttable presumption that they met the “reasonable and good faith effort” standard. Congress should also reduce the time litigants have to bring NHPA claims, make the Record of Decision the final agency action, and limit late-stage injunctions.
For major linear projects with limited federal touchpoints, agencies should conduct early route-level cultural-resource screening rather than either preserving fragmented crossing-by-crossing review or requiring full corridor-wide Section 106 review. High-risk segments identified through screening should receive focused consultation and identification.
Congress and agencies should protect tribal cultural information through stronger FOIA protections, standardized confidentiality protocols, secure-access administrative records, and limited-access review mechanisms for necessary consulting parties. Agencies should be able to document tribal consultation without publicly disclosing sacred-site information.
Congress should provide durable funding for State and Tribal Historic Preservation Officers, compensate tribes when they provide expert identification and evaluation services, and support collaborative field-based models such as the Acoma Model. Agencies should also standardize documentation and metadata requirements and develop centralized, searchable records systems, subject to appropriate confidentiality protections.
Congress should mandate lead-agency designation and coordination for multi-jurisdictional linear projects, expand programmatic agreements and program alternatives for repeat infrastructure categories, and create a clear Federal Energy Regulatory Commission exception to ex parte limits for government-to-government tribal consultation.