Which sections of the US-Mexico border wall are actively monitored and maintained as of December 2025?
Executive summary
As of available reporting, Customs and Border Protection’s “Smart Wall” program documents completed and under‑construction barrier mileage and says roughly 702 miles of primary and 76 miles of secondary barrier existed prior to January 20, 2025, with new projects planned, underway or completed since that date (CBP Smart Wall map summaries) [1]. Federal actions in 2025 — including DHS waivers for about 36 miles in Arizona and New Mexico and multiple contracts for projects in Arizona, California and New Mexico — show active construction, monitoring and maintenance priorities in San Diego, Tucson, El Paso, Yuma and other sectors identified by CBP and DHS [2] [3] [4].
1. What “actively monitored and maintained” means on paper
CBP frames “Smart Wall” as a combined approach of physical barriers, detection technology, patrol access roads and personnel support; the agency’s public Smart Wall materials list barrier status categories — Existing (pre‑1/20/2025), Under Construction and Completed — and describe plans to cover about 535 miles without physical barrier using detection technology where terrain makes fence impractical [1]. CBP’s FAQ emphasizes maintenance attributes (e.g., corrosion‑resistant paint, reinforced steel) as part of construction and upkeep plans [5].
2. Where federal attention and funding are concentrated
Multiple sources show federal activity clustered in Arizona, California, New Mexico and Texas sectors. CBP and reporting note construction restarts and planned projects in the San Diego Sector (California) and in parts of Arizona and Texas; Congress also approved major funding for wall construction and maintenance in 2025 that CBP says will support Smart Wall projects [3] [6] [7] [5]. The White House policy language issued January 2025 explicitly made physical walls and monitored barriers an administration priority [8].
3. Concrete projects and waivers in 2025
DHS issued three waivers to expedite roughly 36 miles of new wall construction in Arizona and New Mexico to speed projects and bypass environmental reviews; DHS described these waivers as intended to “close critical gaps” and reinforce operations in El Paso, Tucson and Yuma Sectors [2]. Reporting and agency announcements also cite CBP contract awards for roughly 27 miles in Santa Cruz County, Arizona, plus work in San Diego and El Paso areas [4] [3].
4. The balance between physical wall and sensors
CBP’s public map and notes make clear that a substantial portion of the 1,954‑mile border is intended to be covered by detection technology rather than continuous physical barrier — CBP explicitly states approximately 535 miles without barrier will be covered by detection systems due to remoteness or unfavorable terrain [1]. Agency materials and the Smart Wall FAQ emphasize combining sensors, patrol roads and manpower with selected physical barriers [5].
5. What the numbers mean — and what they don’t say
The widely cited pre‑2025 totals — roughly 702 miles of primary wall and 76 miles of secondary wall — describe barrier that existed before January 20, 2025; later figures about “completed” or “under construction” miles are reported by CBP but vary by source and contract timing [1] [4]. Available sources do not provide a single, up‑to‑date public list that names every mile‑by‑mile segment currently being patrolled or maintained as of December 2025; instead, CBP’s interactive Smart Wall map and successive contract announcements are the operational record [1].
6. Competing viewpoints and policy context
Administration and CBP communications present the Smart Wall as an integrated security upgrade and cite new funding (including billions in appropriations) to expand construction and maintenance [5] [7]. Advocacy groups and independent reporting note human‑rights and environmental concerns tied to waivers and new construction; WOLA and other outlets documented ongoing debate and reported DHS plans for hundreds of additional miles and related humanitarian concerns [9]. Available sources do not include comprehensive third‑party audits of how well each sector is being monitored day‑to‑day.
7. How to verify specific sectors yourself
CBP’s Smart Wall interactive map is the agency’s central, continually updated public source for status layers (Existing, Under Construction, Completed) and is the primary reference for which segments are officially monitored or slated for maintenance [1]. For project‑level confirmation, look to CBP contract notices and DHS waiver announcements (e.g., the 36‑mile waivers for Arizona/New Mexico) and local reporting in sectors such as San Diego, Tucson, El Paso and Yuma [2] [3] [6].
Limitations: this analysis relies solely on the provided sources; available reporting does not list every actively patrolled mile or provide independent audits of monitoring effectiveness (not found in current reporting).