The US-Mexico border which was placed right through the middle of the unforgiving Atascosa Highlands was put there not out of any geographic necessity or ecological reality, but due to an entangled history of war, political intrigue, and personal interest. Border enforcement in the Atascosa Highlands is driven by the challenging landscape, and recent border wall construction is just one part of the complicated security apparatus that exists here. While U.S. Customs and Border Patrol has grown from a small group of horse mounted inspectors to one of the largest police forces in the world, the border here is the same unmanageable territory encountered by the first boundary survey in the mid 1800’s. Nearly two hundred years after wresting the current borderline from Mexico, and with all the resources available to the United States government, it confounds the ability of either nation to easily control.

            “O this line. Of all the assemblages of folly, ignorance, and hypocrisy I ever saw congregated together under the title of scientific corps, that turned over to me...exceeds.”

- W. H. Emory upon joining the U.S. Boundary Commission

            In 1848, with the U.S. army occupying Mexico City, the government of Mexico signed on to the treaty of Guadalupe-Hidalgo, which for $15 million (about $490 million in 2021), pruned off around 55% of Mexico, and grafted it on to the United States. But whatever satisfaction existed over this treaty on either side was short lived. The boundary commission appointed to survey the new border found that the 25 year old map that the treaty, and their survey, was based on placed the Rio Grande river 130 miles west of where it actually was, and the town of El Paso 40 miles south of its true position. This revelation threw the entire borderline into question. Would the new border be based on the inaccurate map, or the actual position of the Rio Grande? What amounted to a handshake deal was made on the spot by the two lead commissioners from both countries. A compromise that the U.S. would cede the Mesilla Valley (modern day southern Arizona and New Mexico) in exchange for mineral deposits near the Gila mountains. Though the amount of land that the U.S. commissioner passed on was minimal when compared to the whole of the territory added to the U.S. by the treaty of Guadalupe-Hidalgo, there was a fury over this compromise within the membership of the boundary commission and in the halls of power at Washington D.C.

            Many U.S. leaders resented that anything had been granted to Mexico so recently after its defeat in war, and their sense of “Manifest Destiny” was offended. There was also a cadre of southern politicians who desired an all weather southern railroad that could ship goods from the slave states to the newly acquired territory of California, and they wanted this railroad to run through the same Mesilla Valley which the boundary commissioner had agreed to give up. As a result of these objections, the deal made by the Mexican and American boundary commissioners in the field was rejected by congress, and a railroad executive named James Gadsden was sent to Mexico to negotiate the purchase of the disputed territory and anything else the Mexican government would be willing to part with. He arrived like a door to door salesman, with different packages to offer the Mexican leadership. For $50 million the U.S. would be happy to buy most of the remaining northern states of Mexico and Baja, or for $15 million they could buy just the Mesilla Valley from today's Yuma, Arizona to Las Cruces, New Mexico. Cash strapped, Mexican president Antonio Lopez De Santa Anna needed the money to rebuild the Mexican army in case the U.S. got any ideas about taking these territories by force rather than purchase. But he could see that it would be political suicide to take the larger deal, and so he settled on transferring the Mesilla Valley. However, this deal was made over the stringent objections of the vast majority of the Mexican populace who were appalled that Santa Anna would so readily betray the national sovereignty of Mexico. Initially this deal would have drawn a straight line from Las Cruces that would have included a port on the sea of Cortez in the boundaries of modern Arizona. But, Santa Anna would only agree to the deal on the condition that Mexico kept a sliver of real estate as an overland route from Sonora to Baja. So the Mesilla line was redrawn in such a way that the new border would cut northwest from modern day Nogales and slice right through the jagged Atascosa Highlands. The U.S. congress lowered the offer to $10 million (approx $330 million in 2021) and the treaty was ultimately ratified by both countries.

            These newly drawn borders created a host of issues for both countries. One of the top priorities became securing control over goods and people who crossed the line. New municipalities began to pop up along the boundary to facilitate trade and collect duties, but in southern Arizona people who had travelled freely to do business or visit family for generations found themselves suddenly living across an international boundary, and many saw little need to pay these extra costs to engage in the same trade that they carried out before for free. What had always been legitimate trade now became smuggling, and both national governments sought to find ways to gain control over the flow of commerce along this porous boundary.

            For most of the late 19th and early 20th centuries border security consisted primarily of occasional patrols of U.S. army units stationed at towns along the partition. These soldiers were there in large part to restrict the movement of indigenous groups who continued to travel through the landscape as they always had, irrespective of political boundaries, but they would also happen upon people smuggling goods north and south. The town of Arivaca, Arizona was established as a mining camp and a stage stop for people and supplies travelling between Tucson and cities in Sonora, and its placement near the border made it a natural choice for bringing in goods surreptitiously. The rocky highlands south of town were extremely difficult to patrol and monitor, and many people not only took advantage of the lax security, but wanted it to continue. Advocating for opening a store near Arivaca, mining engineer E.B. Gage wrote, “As soon as we get started we can do a big business with Sonora in all kinds of goods. There is a great deal of smuggling between Sonora and Tucson...In this respect it might not be profitable to have a military post too near us.”

            The haphazard enforcement of the political boundary led Congress in 1915, to allocate funds so that a group of mounted guards could be raised to patrol the border. These guards were charged with limiting smuggling and capturing those deemed “illegal immigrants” by the government. At this point that was primarily people of Chinese origin, most of whom were banned from entering the U.S. under the Chinese Exclusion Act of 1882. In 1924 Congress officially created the U.S. Border Patrol to enforce new, more restrictive, immigration laws which set quotas on immigrants from many countries, and helped monitor the spaces between official checkpoints for alcohol smuggling into the U.S. from Canada and Mexico. Until the repeal of Chinese exclusion laws in the 1940’s it was Chinese, not Latin American immigrants who were the primary focus of federal efforts to control migration. But the modern era of border enforcement had yet to begin. As the War on Drugs ramped up through the later part of the 20th century, and in a new post 9/11 world, Border Patrol was folded into the Department of Homeland Security. A massive hiring push saw U.S. Customs and Border Patrol grow from a poorly funded backwater agency, into the largest federal police force in the U.S. with more than 60,000 employees and a budget of around $17 billion in 2020 with another $15 billion being allocated towards border wall construction by private contractors.

            A small army of agents spend their days patrolling Ruby road, and the tiny spur trails that meander through the Atascosas. These agents pull tire drags across the roads to clear them of tracks so that agents can cut fresh sign on the next shift. Utilizing trucks, ATV’s, horses, bikes, and foot patrols to access the varying terrain of the area. For every elaborate strategy developed by Border Patrol, migrants and smugglers are capable of finding simple, inexpensive solutions, and the constant presence of these opposing forces are keenly felt by the residents of nearby border towns. The Border Patrol tire drags can be eluded by migrants with the help of makeshift brooms fashioned together from old garden rake heads, while shoe coverings cobbled together from camouflage fabric and old carpet help deaden the sound of movement and reduce the tracks a person leaves behind.

            Over the last several years Integrated Fixed Towers have begun to pop up across the Highlands. These surveillance towers are outfitted with an array of sophisticated radar and sensor equipment to track movement, and transmit intel to Border Patrol operations bases and agents working in the field. These fixed towers are supplemented by truck-mounted surveillance towers which can be moved around at will. Peeking out from behind Mesquite and oak trees on jagged ridges across this rough wilderness. Mountain peaks are cluttered with large solar powered communications towers that relay cell signals across the low mountains, and steep hills. While throughout the range, smaller field equipment, ranging from commercial wildlife cameras, to tiny antennae tucked into the branches of Mesquite trees, cast a net of surveillance across the rolling grasslands.