So-called "functional class-1" roads can be up to 24 ft wide, while barriers will use steel posts and continuous rails at alternating heights of about 4 ft and 6 ft rather than bollard-style pedestrian barriers. The agency, a unit of the U.S. Dept. of Homeland Security, says the lower-profile design is intended to restrict vehicle access while using the region’s terrain as a natural barrier.

CBP told digital news publication SFGATE that the clearing underway is intended to assess soil conditions and determine excavation depths and base requirements for the planned roads and barriers, and that it does not mark the formal start of BBT-4 construction. The agency did not immediately respond to ENR’s request for clarification on the difference between current work and start of construction.

Marfa Public Radio separately reported seeing Southwest Valley-branded equipment inside the park near Cottonwood Campground Aug. 4.

A coalition of conservation groups, Big Bend-area businesses and national companies have urged Texas state officials to press the Dept. of Homeland Security to abandon the planned roads and physical barriers and instead use technology as an alternative.

“Our senators and governor may be the last line of defense standing between access to the Rio Grande and permanent, irreversible damage,” the coalition said in an Aug. 4 letter to Texas Sens. John Cornyn and Ted Cruz and Gov. Greg Abbott.

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Covering about 1,252 sq miles, Big Bend is larger than Rhode Island and has 304 miles of roads—123 paved, 45 improved unpaved and 136 primitive—according to the National Park Service. Customs and Border Protection says the project will improve existing public and park roads where possible, including all-weather roads and pavement needed for drainage and erosion control.

Marfa Public Radio reports that a planned patrol-road route would cross Mariscal Mountain, which rises about 1,700 ft above the Rio Grande. Texas lawmakers contend the terrain would require blasting; CBP says it “has no plans for blasting of Mariscal Mountain in the Big Bend National Park.”

Kiewit representatives responded to ENR but referred project-specific questions to the agency.

Southwest Valley received the task order through a contracting program established after the department waived federal procurement requirements governing border infrastructure work.

Last October, it invoked Section 102(c) of the Illegal Immigration Reform and Immigrant Responsibility Act, waiving procurement laws for border contracting across Big Bend and eight other Border Patrol sectors. A June Government Accountability Office ruling related to a contractor bid protest says the waivers suspended rules requiring competition among multiple-award contractors for individual task orders, including enhanced competition for orders above $5 million.

Congress expanded the law in 2005 to give the department secretary discretion to waive “all legal requirements” deemed necessary to expedite border barrier and road construction. GAO said the law gives U.S. district courts exclusive jurisdiction over claims arising from actions taken under such waivers, leaving GAO without authority to decide that portion of the contractor’s bid protest. Judicial review is further limited to claims alleging violations of the U.S. Constitution.

ENR reported in May that crews working under a separate Smart Wall contract in Arizona damaged a documented 1,000-year-old Indigenous cultural site that had been identified to avoid. The department waived the National Historic Preservation Act and other federal review requirements for that project, leaving remaining protections largely to Customs and Border Protection contractual and field-level controls.

The department invoked the same federal legislative authority June 9 for the Big Bend contract, waiving NEPA, the Endangered Species Act, Clean Water Act, National Historic Preservation Act, National Park Service Organic Act and numerous other requirements governing activities including earthwork, excavation, drainage, roads and barriers.

The Center for Biological Diversity, Friends of the Ruidosa Church and a Big Bend-area landowner are challenging the waiver in federal court. “Federal environmental laws were passed to keep our national parks wild forever,” said Laiken Jordahl, the Center's national public lands advocate. “It's unconstitutional to waive those laws to bulldoze border barriers and roads through Big Bend.”

Customs and Border Protection says the Big Bend work is intended to combine technology and vehicle barriers with the region's existing natural obstacles.

The agency says it is coordinating road-design requirements with the National Park Service and local officials and intends to maintain access to the Rio Grande and park trails during and after construction.