What sections of the border wall remain incomplete and which areas are prioritized for future construction?
Executive summary
Roughly one-third of the U.S.–Mexico border remains without continuous pedestrian-style barrier, and federal agencies are prioritizing a mix of new bollard fencing, secondary barriers and detection “Smart Wall” technology in sectors with heavy crossings or unfinished system attributes — especially in Texas (Rio Grande Valley and Del Rio), parts of Arizona and New Mexico (including the San Rafael Valley) — while recognizing that rugged terrain and environmental constraints leave long stretches better suited to sensors than steel walls [1] [2] [3] [4].
1. What exists now: miles built and miles missing
Official and independent tallies place border barriers well short of a continuous wall: reporting compiled from government and watchdog sources shows roughly 741 miles of barrier in place at recent counts, of which about 636 miles are pedestrian-style fencing that blocks crossings on foot, leaving large gaps along the roughly 1,954-mile boundary [1]. U.S. Customs and Border Protection (CBP) itself notes that approximately 535 miles of the border will remain without physical barrier and instead be covered by detection technology because of unfavorable terrain or remoteness [3].
2. The nature of the “incomplete” stretches
The incompleteness is not uniform: some gaps are in places where no barrier was ever built because of rivers, mountains or private land; other gaps are “system” gaps where a steel bollard wall exists but associated attributes — roads, cameras, lighting or secondary barriers — were not finished, leaving the physical barrier less effective operationally [5] [2]. CBP and reporting cite dozens of miles where detection technology must be installed to complete the intended “Smart Wall” operational picture even where a fence already stands [2].
3. Where construction is being prioritized now
Federal contracting and project announcements show priority for high-traffic sectors: recent awards target Texas and Arizona projects — for example, five Smart Wall contracts adding 97 miles of primary wall, 19 miles of secondary wall and 66 miles of waterborne barrier systems, plus roughly 149 miles of detection technology where systems remain incomplete [2]. Specific sectors repeatedly named in government releases and media reporting include the Rio Grande Valley and Del Rio sectors in Texas, Arizona stretches, and new or reinforced segments in New Mexico and the San Rafael Valley [2] [6] [7] [8].
4. Concrete projects, contracts and legislative pressure
The federal pipeline combines multi-billion-dollar contracting with new legislative mandates: CBP announced multi-billion-dollar Smart Wall contracts and project awards (total contracts for Smart Wall construction reaching into the billions and specific awards such as the Del Rio 3 Project) while Congress and proposed bills — for example H.R.76 — have sought to compel barrier construction and funding timelines, including deadlines for DHS to “take all actions necessary” to construct barriers and achieve operational control by the end of 2025 [2] [9]. Reporting also documents targeted waivers and expedited procurement to accelerate about tens of miles of construction [10] [7].
5. Strategy: sensors where walls won’t be built
Officials increasingly treat the border as a mixed system: where geography or remoteness make continuous fencing impractical or environmentally fraught, CBP plans to deploy detection technology and integrate it with built barriers — the so-called Smart Wall — rather than force steel through deserts, rivers and mountains [3] [5]. Independent analysts and advocacy groups note that rugged terrain and tunnels historically limit the utility of a continuous physical wall, reinforcing a pragmatic split between physical and technological approaches [4].
6. Pushback, environmental cost and local politics
Construction priorities meet sustained opposition from local communities and conservation groups: reporting documents lawsuits and grassroots resistance in places like Laredo and ecological critiques from groups such as Sky Island Alliance and Wildlands Network, which point to graded access roads, groundwater pumping, river impacts and wildlife fragmentation from both past and proposed projects [11] [8] [12]. Those concerns have influenced where and how agencies choose to place barriers versus relying on detection technology, even as federal waivers and political pressure speed work in contested spots [10] [6].