June 15, 2026

The Honorable Markwayne Mullin Secretary

United States Department of Homeland Security 

Dear Secretary Mullin:

We write to you again, following up on our letter from May 21, 2026. We are six former superintendents and a former deputy superintendent of Big Bend National Park, with over 250 collective years of National Park Service (NPS) experience.

In our previous letter, we urged you to reject the waiver of federal laws that would allow physical barriers and roads, as well as related border security infrastructure, to be built inside the park in the absence of environmental or cultural compliance or public involvement.

On June 9, 2026, you waived not just those federal laws, but all state and local laws and regulations, and legal requirements deriving from, or related, to the subject of, the federal statutes you summarily overrode.

This was devastating news, though not unexpected.

We write today to respectfully suggest that it is still possible to enhance border security in Big Bend National Park without destroying what makes it one of America’s most treasured landscapes. But it will take a commitment on your part, and enforced restraint on the part of your contractors, to avoid wholesale and unaccountable destruction of the park’s natural, cultural, and scenic resources, as well as a major negative hit to the region’s tourism-dependent economy.

The inconsistencies between the public statements that Customs and Border Protection (CBP) Commissioner Scott has made and the plain language of the recently-awarded $1.7 billion contract and the information on CBP’s just-published “StoryMap” website are stark–and leave us, and all concerned Americans, wondering what your actual intent is in the national park, and whether any statements put out by DHS or CBP officials can be relied upon.

Commissioner Scott was quoted in the Washington Examiner on May 4, 2026, that “CBP will not build a border wall inside Big Bend National Park on the U.S.-Mexico border following blowback from local residents.”

In letters to 19 Congressional representatives written May 21, 2026, representing the Department, Mr. Scott wrote that “the Big Bend area contains some of the most unique and important scenery and archeological landscapes in Texas, and it is valued accordingly. Big Bend National Park and its related areas also provide support for the local and regional economy. DHS recognizes this along with the intrinsic importance these areas hold for Texans and others who visit and enjoy them. Border security measures in the Big Bend National Park or the Big Bend Ranch State Park will be adapted to the terrain; and they will use technology, such as cameras and sensors, along with a limited number of low-profile vehicle barriers and patrol roads strategically placed to leverage the landscape that serves as a natural deterrent. Additionally, lighting will not be installed due to environmental considerations and operational requirements.”

He went on to write that project planning would be done in collaboration with federal and state partner agencies, and “CBP’s goal is to balance operational needs with responsible stewardship of the land and minimize harm to the greatest extent practicable in accordance with applicable law while still meeting CBP’s operational requirements.”

If this is true, what are the sideboards for DHS’ plans? Why issue a contract for a staggering

$1.7 billion for construction of a “border wall in Big Bend Texas, segment identified as BBT-4”? We’ve seen statements that indicate that despite the plain language, DHS has no intention of building an actual border wall.

We have grave concerns over the waiver you issued on June 9, which allows for “the construction of physical barriers and roads (including, but not limited to, accessing the project areas, creating and using staging areas, the conduct of earthwork, excavation, fill, and site preparation, and installation and upkeep of physical barriers, roads, supporting elements, drainage, erosion controls, safety features, lighting, cameras, and sensors) in the project area.”

Furthermore, DHS’ description of the project includes 205 miles of new roads up to 24 feet wide, staging areas and laydown yards, lighted utility poles near the Port of Entry (which sees absolutely no illegal entries), buried power and fiber optic cables, 30- x 30’ utility shelters, and

unspecified water use in an environment where water is scarce and endangered species rely on groundwater springs.

The waiver also just overrode “all applicable law” that Commissioner Scott pledged to respect.

You now seem to believe you have unlimited authority and no legal accountability. While we wish it were otherwise, we nonetheless appeal to your patriotism and commitment to the full range of what makes America great by doing everything possible to minimize unnecessary impacts to Big Bend National Park. A secure border and conserving America’s natural and cultural resources do not have to be in conflict.

Accordingly, we recommend the following:

  • Vehicle Barriers: CBP proposes 17 miles of metal vehicle barriers, in 4 locations. As there is no history, nor risk, of vehicles crossing the Rio Grande at the two middle locations, we urge you to strike these from your plans. While our collective experience indicates that the risk at the two other locations is extremely low, any vehicles that did successfully cross the Rio at these locations would immediately head for the nearest paved roads, which are located just a few miles away outside park boundaries. Restrict these barriers to lands outside the park, and they will accomplish the same purpose. We also ask for assurances that non-vehicular access to public lands in the national park not be restricted by any vehicular barriers.
  • Additional Patrol Roads: There are already paved and unpaved roads that roughly parallel most of the border in the national park, regularly utilized by U.S. Border Patrol (USBP) agents for their patrols. While the 51-mile unpaved River Road is not as close to the Rio Grande as the proposed new road, it is where migrants that do manage to cross the Rio Grande in the park are most frequently apprehended. There is no security benefit to apprehending them a bit closer to the river. Upgrade the River Road if it is necessary, preferably no higher than the standard long ago agreed-to by the agencies on the ground. Constructing a new parallel road would cause huge devastation to a vast unroaded section of the national park, in some cases requiring blasting of mountains. It would also unnecessarily violate, in some areas, a wilderness recommendation supported by the NPS under all administrations since it was proposed by Richard Nixon in 1973. It would hardly “leverage the landscape that serves as a natural deterrent,” as Commissioner Scott committed
  • Sensors and Communication and Power Cables: There are currently hundreds of electronic surveillance devices in the national park and surrounding areas, maintained jointly by USBP, NPS, and county sheriffs. These are all battery or solar powered,

communicate wirelessly, and in almost all cases visually and environmentally unobtrusive. The local power grid is notoriously unreliable, with blackouts often lasting for days. Many of the areas proposed for underground cables are in unstable environments subject to severe flash flooding; others, in rocky terrain, would require blasting to construct. Fiber optic cables will quickly be technologically obsolete.

We urge you to reconsider the sensor configuration and improve or enhance the existing network with updated technology and improved wireless communications. It would be far less intrusive, quicker to deploy and more nimble to move to other areas if the needs change, less environmentally destructive, and a vast saving of taxpayer funds. We are also concerned that in the absence of any meaningful and enforceable oversight by the NPS, commitments by DHS or its contractors to limit impact to narrow corridors adjacent to roads give us no confidence that the impacts would be minimal.

It is our understanding that advanced aerial surveillance systems, including high altitude drones have been successfully used for detection purposes in other areas of the border with great success, and as you know, these have been recommended by the local sheriffs who know the border and security issues in this area as well as anyone.

  • Laydown and Staging Areas and Construction Camps: Big Bend National Park is the most sensitive environment on the entire U.S.-Mexican border. Clearing of large areas to facilitate construction, again in the absence of oversight or accountability by the NPS, will unnecessarily damage park resources and cause permanent visual scars. We urge you to keep these to existing paved sites in the park or to use areas outside park boundaries. There is not enough water or wastewater capacity in the park’s utility systems to accommodate large number of workers, and with DHS waiving the NPS Organic Act and General Authorities Act, it’s unclear if NPS would even be able to enforce unrelated park rules if needed to restrain the conduct of workers even when they are not on the job. If you reduce the scope of the project as we have suggested, the number of workers and the footprint to support them will also be reduced.
  • Water Use: Please truck in all water needed for construction activities rather than overtax the parks’ existing wells and delivery systems. New wells would further deplete precious groundwater resources needed both for park residents and visitors, as well as wildlife, including endangered animals. While you have waived the Endangered Species Act, you don’t have to violate its intent with impunity.
  • Lighting: Your published plans indicate that utility poles near the Boquillas Port of Entry will be lit, and shielding may be installed to reduce light spillage. That contradicts

Commissioner Scott’s commitment that there will be no lighting. We urge you to do as Mr. Scott said you would.

There does not need to be a conflict between a strong border, a thriving local economy, and conservation of the wildest, most intact landscapes of Texas and our nation. If Customs and Border Protection would meaningfully engage the public, local elected officials, sheriffs, and the National Park Service in a sincere effort to improve border security and to—as Commissioner Scott said, representing you—minimize harm to the greatest extent practicable, we are absolutely confident that there are solutions that would satisfy your operational needs and not unduly harm one of the nation’s most iconic national parks. It would also have the potential to rebuild trust with the people of Texas, which has been severely damaged by your Department’s unilateral actions to date.

We are pleased to see that you have opened a comment period. Please show the American people that you take their views seriously, and suspend all planning and do nothing on the ground in the national park until those comments are analyzed, published, considered, and your plans are modified in response and again shared with the public.

Sincerely,

Bob Krumenaker, Superintendent 2018 – 2023, and Chair, Keep Big Bend Wild David Elkowitz, Deputy Superintendent 2019 – 2022

Cindy Ott-Jones, Superintendent 2012 – 2017

Bill Wellman, Superintendent 2006 – 2012 John H. King, Superintendent 2003 – 2006 Robert Arnberger, Superintendent 1991 – 1994

H. Gilbert Lusk, Superintendent 1981 – 1986