Trump Administration’s Big Bend Border-Wall Plan Calls for Road Across Mariscal Mountain

The U.S. Customs and Border Protection (Customs and Border Protection’s (CBP)) “Smart Wall” plan for the Big Bend sector proposes a new patrol road that would cut across Mariscal Mountain, a nine-mile limestone ridge rising to 3,932 feet inside Big Bend National Park. Federal maps show the route passing near Mariscal Canyon and the Rio Grande. The Center for Biological Diversity said on August 6 the planned route would require “extensive dynamite blasting” because of the mountain’s rugged terrain.

Newsweek

Conservation groups and local officials argue the road would damage desert habitat, threaten endangered peregrine falcons, and jeopardize tourism-driven economies. Former park wildlife biologist Raymond Skiles warned that construction could disturb one of Texas’ most densely populated peregrine nesting areas. A coalition of ten House Democrats, writing on July 31, urged the administration to halt work until detailed designs and rock-disposal plans are disclosed, citing potential violation of a 1970 U.S.–Mexico boundary treaty if blasting sends debris into the Rio Grande.

Newsweek

CBP Commissioner Rodney S. DHS and CBP officials argue the improvements will help agents detect illegal crossings, respond faster, and prevent cartels from exploiting the area.

Newsweek

CBP data show a sharp decline in encounters within the Big Bend sector: 148 migrant encounters were recorded in June 2026, down from 412 in June 2023. In the first nine months of fiscal 2026, 1,509 encounters were logged, an 85 percent drop from 10,291 in the same period of fiscal 2023. The agency cites more than 89,000 migrant encounters between fiscal years 2021 and 2025, alongside drug seizures, as justification for the project. The Smart Wall plan also includes roughly 205 miles of detection systems in the sector.

Newsweek

> “I’ve hiked the Mariscal Canyon Trail, which is about a 6.5-mile round trip to a canyon with walls reaching roughly 1,500 feet. People simply don’t cross there. Even if they did, they would face approximately a 110-mile walk to reach an area where they could realistically be picked up.” — Sheriff Thaddeus Cleveland (Texas border sheriff)

Newsweek