Documented Tribal Privacy and Cultural Harms Can Justify Prohibiting National-Park Air Tours

1. Introduction

This case concerns whether federal agencies may prohibit commercial sightseeing flights over a national monument when their principal harms involve tribal privacy, sacred landscapes, and interference with cultural and religious practices rather than aircraft noise alone.

Bruce Adams, operating Southwest Safaris without counsel, challenged an Air Tour Management Plan adopted jointly by the Federal Aviation Administration and National Park Service. The plan prohibited commercial air tours within its boundary at Canyon de Chelly National Monument. Adams argued that his flights caused no significant harm, that the agencies had violated environmental-review requirements, and that the governing statute was unconstitutional.

The Tenth Circuit rejected those challenges. It concluded that the administrative record supported findings of significant adverse effects on Navajo cultural resources and privacy, and that the agencies adequately explained why route changes and time restrictions would not resolve those effects.

Background and competing interests

Canyon de Chelly encompasses approximately 84,000 acres entirely within the Navajo Nation Reservation. More than 600 Navajo residents live within the Monument. Its cultural resources include archaeological and ancestral sites, sacred places, traditional cultural properties, and the continuing relationships between Navajo people and the landscape.

Southwest Safaris had operated educational air tours in the Southwest since 1974. Following enactment of the National Parks Air Tour Management Act of 2000, four operators received interim authority for 175 annual tours over the Monument, including 147 allocated to Southwest Safaris. Since 2017, Southwest Safaris was the only operator reporting tours there. It averaged 43 annually during 2017–2019 and reported 82 in 2023.

The agencies initially proposed allowing 43 annual tours. Consultation revealed extensive Navajo opposition: all five chapters representing communities in and around the Monument adopted resolutions opposing overflights, and the Navajo Nation President supported their position. Those responses identified interference with ceremonies, privacy, residential life, and the sacred character of the landscape. The agencies subsequently proposed, and ultimately adopted, a prohibition.

2. Summary of the Opinion

The court exercised direct-review jurisdiction under 49 U.S.C. §§ 40128(b)(5) and 46110(a), noting that Southwest Safaris maintained its principal place of business in New Mexico.

Its principal conclusions were:

1. The statutory prerequisite was satisfied. The agencies identified significant adverse impacts before prohibiting commercial air tours, as required by NPATMA and Adams I.
2. The record supported cultural and privacy harms. Input from the Navajo Nation President, local chapters, and individual residents reasonably supported the agencies’ findings.
3. Low noise did not resolve the relevant concerns. Physical presence, perceived observation, and intrusion into sacred activities could produce significant impacts independently of sound levels.
4. The prohibition was adequately justified. Sensitive locations were distributed throughout the Monument, while traditional activities occurred throughout the day, making route and scheduling restrictions inadequate.
5. The environmental and historic-preservation challenges failed. The court found no violation of NEPA or NHPA in the agencies’ preparation and adoption of the plan.
6. The constitutional challenges provided no basis for relief. Some failed on their merits; others were inadequately developed.

The court therefore denied the petition, leaving the final plan in place.

3. Statutory Framework and Standard of Review

NPATMA: protection requires an identified impact

NPATMA directs the agencies to develop “acceptable and effective measures” to mitigate or prevent significant adverse impacts of commercial air tours on natural and cultural resources, visitor experiences, and tribal lands. Available measures include route, altitude, and timing restrictions, as well as partial or complete prohibitions.

That authority is not unconditional. Under Adams I, a finding of significant adverse impacts must precede restrictions. Section 40128(b)(3)(F) also requires the agencies to justify and document their selected measures. The statutory inquiry therefore has two central components:

• Do commercial air tours produce significant adverse impacts within the statute’s protective purposes?
• Has the agency reasonably explained how its chosen restrictions address those impacts?

NPATMA additionally requires participation by affected tribes and expressly recognizes intrusions on privacy on tribal lands as a relevant regulatory concern.

APA review: deferential, but explanation-dependent

The Administrative Procedure Act required the court to determine whether the agencies acted arbitrarily, capriciously, abusively, or contrary to law. The court did not decide for itself how many flights Canyon de Chelly should accommodate. It examined whether the agencies’ decision was reasonable and supported by an intelligible explanation grounded in the record.

This standard combines deference with accountability. An agency need not produce a perfectly written decision, but the court cannot invent missing reasons or accept explanations supplied only by litigation counsel.

4. Legal Reasoning

A. Tribal consultation supplied evidence of protected harms

The court treated tribal participation as a substantive source of information, not merely a procedural formality. The agencies consulted the Navajo Nation President’s office, relevant departments, nearby chapters, and individual residents. Their responses described how overflights affected particular interests: ceremonial privacy, freedom to conduct traditional practices, residential tranquility, and cultural relationships with sacred places.

The distinction between tangible and intangible resources was important. Cultural protection extended beyond preventing physical damage to archaeological sites. It also encompassed the ability to use sacred places for ceremonies, prayer, reflection, and other traditions.

The decision does not establish an automatic tribal veto over air tours. The agencies remained responsible for making statutory findings and explaining their response. Here, detailed tribal input supported those findings, and the court found that reliance reasonable.

B. Minimal noise does not establish minimal cultural impact

Adams maintained that his aircraft were quiet, did not circle, and followed routes offset from the canyons. Those assertions did not answer the agencies’ principal concerns. The relevant harms included intrusion upon ceremonies and the aversion to performing traditional practices under observation.

The court accordingly rejected the premise that an unheard aircraft necessarily causes no significant impact. NPATMA separately recognizes privacy interests, and cultural interference may arise from an aircraft’s presence rather than its acoustic intensity.

This reasoning remains tied to the record. The court did not hold that every overflight necessarily creates significant cultural harm. It upheld findings concerning this Monument, its continuing residential and ceremonial uses, and the information provided by affected Navajo communities.

C. Commercial air-tour status depended on operational evidence

Adams also suggested that his flights merely transported passengers to Chinle or other parks and therefore were not commercial air tours. The agencies reasonably rejected that characterization using the statutory factors in 49 U.S.C. § 40128(g)(4)(B).

Relevant evidence included Southwest Safaris’ website, its narration about locations within the Monument, and its own reported air-tour activity. A transportation destination did not negate those operational characteristics. The ruling therefore upheld a record-based classification rather than establishing that every flight passing over the Monument is an air tour.

D. The agencies reasonably explained why narrower restrictions would fail

A finding of harm did not alone answer whether a complete prohibition was justified. The court separately examined the agencies’ explanation for rejecting less extensive operational controls.

The agencies identified two connected difficulties:

• Spatial: Sensitive places were densely distributed throughout a monument shaped by its canyons and waterways, making rerouting ineffective.
• Temporal: Traditional practices and ceremonies occurred throughout the day, making time-of-day restrictions inadequate.

The record supported both explanations. The court therefore found the prohibition to be an acceptably justified response under NPATMA. It did not impose a constitutional least-restrictive-means test; it applied the statute’s requirements of effective mitigation and documented justification.

E. Last-minute route changes did not require restarting the analysis

The agencies had requested and used flight information supplied by Southwest Safaris. Adams did not identify errors in that original information, but notified the agencies of changed flight patterns two days before the final plan issued.

The court held that reliance on the previously supplied information was not an abuse of discretion. Otherwise, operators could continually change routes and require agencies to repeat completed analyses, preventing decisions from becoming final.

This is a practical finality principle, not an unlimited exemption from considering new information. The holding addressed the timing and circumstances of Adams’s particular submission.

F. Existing tourism did not eliminate tribal privacy

Adams pointed to ground tours and visitors driving along canyon rims to characterize the Monument primarily as a recreation area. The court rejected the inference that public visitation extinguished protected privacy interests.

The Monument remained Navajo tribal trust land occupied by residents and used for cultural and religious practices. The presence of one form of tourism did not require agencies to treat another as harmless or equivalent.

5. NEPA and NHPA: Separate Duties, Not Contradictory Findings

Different statutes ask different questions

Adams argued that a NEPA finding of no significant impact contradicted the NPATMA finding of significant adverse impacts. Following Adams I, the court rejected that argument because “significant” carries different meanings within the two statutory schemes.

The distinction also reflects the objects of review. The agencies assessed the environmental consequences of their proposed plan, while NPATMA required them to evaluate the adverse effects of commercial air tours. A finding that adopting a prohibition does not require a full environmental impact statement is not inherently inconsistent with a finding that the regulated flights harm protected cultural interests.

Procedural review did not displace substantive protection

NEPA required an adequate environmental assessment of agency action; it did not dictate whether tours must continue. NHPA required consideration of effects on historic properties. NPATMA supplied the substantive obligation to address significant adverse impacts from air tours.

The agencies prepared an environmental assessment comparing continued operations with prohibition. For NHPA purposes, they consulted the Navajo Nation’s Tribal Historic Preservation Officer, 23 other tribes, Apache County, the National Parks Conservation Association, and Adams. The FAA found that the prohibition would not adversely affect historic properties.

The court found no unlawful conflict in the agencies’ use of these procedures while developing the plan. It also rejected Adams’s alternatives objection, including his proposed “safety corridor” at 1,000 feet above ground level.

Limit of the ruling: The opinion addressed these environmental-review objections relatively briefly. It should not be read as establishing that two alternatives always satisfy NEPA, or that consultation alone invariably establishes NHPA compliance. Its approval concerned the process and record before it.

6. Constitutional Challenges

First Amendment

Adams argued that the statute targeted scenic interpretation because narration helps determine whether a flight qualifies as an air tour. The court distinguished regulating speech from using speech as evidence of regulated commercial conduct.

Narration was one classification factor, not the object of the prohibition. The government regulated commercial flight activity and its effects, rather than suppressing a particular interpretive message. Any resulting burden on narration was incidental to that regulation.

Procedural due process

The court rejected the Fifth Amendment due process challenge because the agencies provided the procedures NPATMA required, including public availability of the proposal, notice and comment, and public meetings. Adams submitted extensive comments, and the agencies held two meetings.

The opinion did not undertake an extended analysis of whether interim operating authority constituted a protected property interest. Its stated conclusion concerned the adequacy of the process actually provided.

Equal protection

Adams challenged distinctions among commercial flights and among parks, including an exemption concerning flights over Lake Mead en route to Grand Canyon tours. Those distinctions involved neither suspect nor quasi-suspect classifications, so rational-basis review applied.

Under that deferential standard, Adams had to negate every conceivable supporting basis. He did not attempt to do so. The rejection therefore rested substantially on his failure to develop the required argument, not on a detailed judicial evaluation of every statutory distinction.

Port Preference and Commerce Clauses

The court declined to entertain these theories because Adams offered only conclusory assertions. Their rejection was based on inadequate briefing, not a comprehensive merits holding about either constitutional clause.

The court also rejected his assertion that the statutory description of the national parks as a “single national heritage” required identical treatment of every park. The same provision recognizes their distinct character.

Ex Post Facto Clause

The challenge failed because the Ex Post Facto Clause concerns penal legislation, while NPATMA does not impose criminal penalties. Earlier operation of a business did not convert later civil regulation into prohibited retroactive punishment.

Nondelegation

The statute supplied an adequate “intelligible principle” for agency action. Congress identified both the policy—preventing significant adverse impacts on specified resources and interests—and the boundaries of agency authority through provisions stating what plans must and may contain.

The court therefore rejected the contention that Congress had transferred legislative power without sufficient direction.

7. Precedents Cited and Their Influence

A. Direct authority and administrative review

Adams v. FAA (“Adams I”), 168 F.4th 1271

This was the central authority. In reviewing another air-tour plan challenged by Adams, it required a significant-adverse-impact finding before restrictions under NPATMA. The present court applied that requirement and found it satisfied. It also relied on the earlier decision’s distinction between NPATMA and NEPA significance, its recognition of privacy-based harms, and its treatment of due process and inadequately developed constitutional arguments. The present opinion is principally an application of that framework to Canyon de Chelly.

Motor Vehicle Mfrs. Ass'n of the U.S., Inc. v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29

This decision supplied two limits on judicial deference: courts cannot invent a rationale the agency did not give, and appellate counsel cannot cure a decision through post hoc explanations. Its importance here is that the agencies themselves had documented the cultural harms and reasons for prohibition.

Seven Cnty. Infrastructure Coal. v. Eagle Cnty., 605 U.S. 168

The court used this authority for the “reasonable and reasonably explained” formulation of administrative review. It also relied on its characterization of NEPA as procedural rather than a source of substantive environmental commands. Together, those propositions framed both review of the prohibition and rejection of the claimed conflict among statutes.

Garland v. Ming Dai, 593 U.S. 357

This case supported upholding an agency decision of less than ideal clarity when its reasoning can reasonably be discerned. It allowed review of the agencies’ actual explanatory path without demanding perfect drafting.

Encino Motorcars, LLC v. Navarro, 579 U.S. 211

The court cited this decision for the requirement that an agency explanation be “clear enough.” Read with the preceding authorities, it marked the boundary between tolerable imperfections and an inadequately explained decision.

B. Decision-making finality and environmental review

Badger Helicopters Inc. v. FAA, 154 F.3d 902

This aviation-specific authority warned that requiring repeated analysis whenever tour operators alter their flight patterns could make decision-making intractable. It directly supported rejecting Adams’s demand that the agencies respond to route changes disclosed two days before issuance.

Hillsdale Env't Loss Prevention, Inc. v. U.S. Army Corps of Eng'rs, 702 F.3d 1156

This Tenth Circuit decision reinforced the need for agencies to have discretion to draw a line and proceed with decisions. It supported reasonable administrative closure, rather than an obligation to restart whenever a regulated party changes its proposal.

Diné Citizens Against Ruining Our Env't v. Bernhardt, 923 F.3d 831

This case explained the review mechanism: neither NEPA nor NHPA supplies a private right of action, so compliance is reviewed through the APA as final agency action. It supplied the procedural framework for Adams’s environmental and historic-preservation claims.

C. First Amendment authorities

Sorrell v. IMS Health, Inc., 564 U.S. 552

The court relied on the proposition that regulation directed at commerce or conduct may incidentally burden speech. That distinction supported treating the air-tour restrictions as regulation of flight operations rather than censorship of scenic narration.

Flytenow, Inc. v. FAA, 808 F.3d 882

This decision upheld the FAA’s use of online speech as evidence that pilots held themselves out as common carriers. By analogy, Southwest Safaris’ advertising and narration could help classify its operations without making the speech itself the regulatory target.

Rumsfeld v. F. for Acad. & Inst. Rts., Inc., 547 U.S. 47

This authority established that conduct does not become constitutionally immune merely because language initiates, evidences, or helps carry it out. It reinforced the distinction between commercial flight activity and its accompanying narration.

Chiles v. Salazar, 146 S. Ct. 1010

Adams submitted this conversion-therapy decision as supplemental authority. The court expressly found it unhelpful to his NPATMA challenge. It therefore played no affirmative role in the holding, and the opinion did not develop a broader comparison between the two regulatory settings.

D. Equal protection and adequate briefing

Brown v. Montoya, 662 F.3d 1152

This decision supplied the classification-based framework for selecting strict scrutiny, intermediate scrutiny, or rational-basis review. Because Adams challenged commercial-flight and park classifications, the court selected rational-basis review.

Heller v. Doe ex rel. Doe, 509 U.S. 312

This authority imposed the demanding challenger’s burden of negating every conceivable basis supporting a nonsuspect classification. Adams’s failure to address that burden defeated his equal protection argument.

Bolling v. Sharpe, 347 U.S. 497

The court cited this case when explaining that the Fourteenth Amendment applies to states, not the federal government. Adams’s challenge to federal legislation was therefore addressed under the Fifth Amendment.

Harsco Corp. v. Renner, 475 F.3d 1179

This decision supported treating inadequately addressed opening-brief arguments as waived. It supplied the procedural basis for rejecting the cursory Port Preference Clause and Commerce Clause theories without resolving their full merits.

E. Penal legislation and delegated authority

Kansas v. Hendricks, 521 U.S. 346

The court relied on this decision’s limitation of the Ex Post Facto Clause to penal statutes. Because NPATMA imposed no criminal penalties, Adams’s theory failed at that threshold.

FCC v. Consumers' Rsch., 606 U.S. 656

This case supplied the governing nondelegation inquiry: whether Congress provided an intelligible principle directing the agency. Its focus on statutory policy and boundaries structured the court’s examination of NPATMA.

J.W. Hampton, Jr., & Co. v. United States, 276 U.S. 394

Quoted through FCC v. Consumers' Rsch., this foundational authority supplied the “intelligible principle” formulation. It did not establish an additional test separate from the one the court applied.

Am. Power & Light Co. v. SEC, 329 U.S. 90

Also quoted through the contemporary nondelegation decision, this case identified Congress’s statement of general policy and the boundaries of delegated authority as relevant guideposts. The court found both in NPATMA’s objectives and its mandatory and permissive provisions.

F. Contextual authorities

Garrett v. Selby Connor Maddux & Janer, 425 F.3d 836

This case explained the treatment of Adams’s self-represented filings: liberal construction without judicial advocacy. It contextualized why the court considered his theories while still enforcing briefing requirements.

Hydro Res., Inc. v. EPA, 608 F.3d 1131

This decision supplied the description of a Navajo chapter as a tribal political and social unit. Its role was explanatory, clarifying the institutional character of the chapter resolutions rather than determining the substantive validity of the prohibition.

8. Potential Impact and Limits

Protection of living cultural landscapes

The opinion illustrates how NPATMA can protect ongoing cultural relationships with land, not merely physical objects. Future decision-makers may find its treatment of ceremony, privacy, and sacred space persuasive where those interests are supported by a developed record.

Meaningful use of tribal knowledge

The decision supports treating affected communities’ accounts as evidence of cultural effects. Agencies should nevertheless connect consultation responses to statutory interests and explain why particular controls address the identified harms. Collecting objections without analysis would not reproduce the reasoning upheld here.

Noise analysis is not the complete inquiry

Operators challenging restrictions may need to address cultural and privacy impacts directly. Evidence of quiet aircraft, brief flights, or routes outside canyon sightlines may not rebut findings directed at different harms.

Complete prohibitions require their own explanation

The agencies prevailed because they documented both significant impacts and the inadequacy of rerouting and scheduling. The opinion does not suggest that an impact finding automatically validates the broadest available restriction.

Limited constitutional reach

The First Amendment and nondelegation rulings provide persuasive applications of established doctrine. By contrast, the inadequately briefed constitutional claims offer little guidance on their underlying merits.

Above all, this remains a nonprecedential, record-specific decision. It does not establish an automatic prohibition for sacred landscapes, an unrestricted tribal veto, or a general rule that environmental review may disregard reasonable alternatives.

9. Complex Concepts Simplified

Arbitrary-and-capricious review

A court checks whether an agency considered the relevant issues and reasonably explained its decision; it does not simply choose its preferred policy.

Administrative record

The materials before the agencies when they acted, including comments, consultation responses, studies, and their explanations.

Intangible cultural resources

Cultural relationships and practices—such as ceremonies and connections to sacred places—that matter even without physical damage to a site.

Finding of no significant impact

A NEPA determination that the proposed federal action does not require a full environmental impact statement. It does not mean that every activity discussed in the assessment is harmless.

Rational-basis review

A deferential constitutional test under which ordinary classifications generally survive if a conceivable legitimate reason supports them.

Intelligible principle

Congressional guidance sufficient to direct and limit an agency’s exercise of delegated authority.

Post hoc rationalization

A justification supplied after the decision, particularly during litigation, rather than the explanation on which the agency actually relied.

Preclusion and law of the case

Doctrines that can make a decision controlling in the same litigation or prevent parties from relitigating resolved claims or issues, even though the decision is not binding precedent for unrelated cases.

10. Conclusion

Adams v. FAA demonstrates that documented interference with tribal privacy and cultural practices can justify prohibiting commercial air tours, even when aircraft noise is disputed or limited. The decisive features were meaningful consultation, supported findings of significant adverse impacts, and a reasoned explanation of why narrower controls would fail.

Its broader lesson is methodological rather than categorical: agencies must identify the protected harm, connect it to the record, and justify their response. This nonbinding decision persuasively applies that approach to a living Navajo cultural landscape.