At Sierra Vista Ranch in Arizona near the Mexican border, Troy McDaniel is warming up his helicopter. McDaniel, tall and slim in a tan jumpsuit, began taking flying lessons in the 80s, and has since logged 2,000 miles in the air. The helicopter, a cosy, two-seater Robinson R22 Alpha is considered a work vehicle and used to monitor the 640-acre ranch, but it’s clear he relishes any opportunity to fly. “We will have no fun at all,” he deadpans.McDaniel and his wife, Melissa Owen, bought their ranch and the 100-year-old adobe house that came with it in 2003. Years before, Owen began volunteering at the nearby Buenos Aires National Wildlife Refuge, and fell in love with the beauty and natural diversity of the area, as well as the quiet of their tiny town. That all changed last July when construction vehicles and large machinery started “barrelling down the two-lane state road”, says Owen.Once work on President Donald Trump’s border wall began, construction was rapid. Sasabe, a sleepy border town, located over an hour from the nearest city of Tucson, was transformed into a construction site. “I don’t think you could find a single person in Sasabe who is in favour of this wall,” Owen says.The purpose of our helicopter trip today is to see the rushed construction work occurring just south of the couple’s house, as contractors race to finish sections of the border wall before Trump leaves office. Viewed from high above the Arizona desert, in the windless bubble of the cockpit, this new section of wall stretches across the landscape like a rust-coloured scar. McDaniel guides us smoothly over hills and drops into canyons, surveying the beauty of the landscape. Here, as on much of the border, the 30ft barrier does not go around; it goes over – stubbornly ploughing through cliffs, up steep mountainsides, and between once-connected communities.“That was already a pretty good barrier,” McDaniel says of the steep, unscalable cliff in front of us. The bulldozed path of Trump’s wall creeps up over the mountain’s west side, but on the other side of the cliff there is no wall, just a large gap. As with many areas on the border, the wall here is being built in a piecemeal fashion. According to the US Army Corps of Engineers, there are 37 ongoing projects, of which only three are set to be completed this month; others have completion dates as far away as June 2022.In August, at a virtual press conference with the National Association of Hispanic Journalists, Joe Biden told reporters that “there will not be another foot of wall constructed on my administration”. The 37 existing construction sites, in various stages of completion, are likely to be shut down.Yet he will have to formulate a more complex policy than simple suspension. Many of the private contractors building the wall have clauses in their contracts that will trigger large payouts if the government simply stops construction. There are also ongoing legal cases brought by private landowners from whom the government seized land. The exact nature of these obligations may only be clear to Biden once he takes office.In the meantime, Trump has accelerated building in the wake of the election, with crews working flat out, late into the night. Throughout December and into January, mountainsides were exploded with dynamite and large portions of desert bulldozed, to make way for a wall that may not be finished in time.For the past four years, I have been living in New Mexico, travelling in the borderlands and documenting the ongoing impact of the wall on communities and the environment.“They started working nights six weeks ago,” says photographer John Kurc, who has been documenting construction in the remote Guadalupe Canyon in Arizona since October last year. “It’s been nonstop ever since.”This is not about protecting America. It’s about protecting President Trump’s own interestsVerlon Jose, former vice-chair of the Native American Tohono O’odham Nation, tells me he has seen the wall plough through his ancestral homeland. “We are caretakers of this land. We are responsible for these things. Has anyone ever asked for permission from the local folks to do the construction? This is about President Donald Trump. It’s not about protecting America. It’s about protecting his own interests.”When construction stops, there will be large gaps in the new wall. In some places it will join up with older barriers that the Trump administration deemed inadequate; in others it will finish abruptly. “They work as fast as they can to build walls that will just end,” says McDaniel, as his helicopter circles back toward their property over saguaro-studded hillsides just north of the Mexican border. We drop altitude and approach the landing strip – a patch of dirt just off the road – whipping up a small dust storm as we touch the ground.***After four years of daily scandals, and the shocking scenes in Washington DC last week, it’s easy to forget that Donald Trump was elected in 2016 with one signature policy: to build a wall. That was the call echoed at his rallies, the embodiment of Trump’s hardline approach to immigration and his purported “America First” ideology. Trump claimed the wall would address an invasion of undesirable migrants, “bad hombres”, a nationalist rhetoric that resonated with his base. During his first week in office, Trump signed an executive order that included a policy for “the immediate construction of a physical wall on the southern border”.Construction began in 2019, mostly replacing existing fences, vehicle barriers, and other border structures, as well as unwalled sections of the border. The bollard wall, Trump’s barrier of choice, consists of a series of vertical steel posts set in concrete, with small gaps in between. While in some places it reaches a height of 30ft, it is less of a wall and more of an imposing metal fence.According to Kenneth Madsen, an associate professor in the department of geography at Ohio State University, the Department of Homeland Security (DHS) has waived 84 laws and statutes – many enacted specifically to protect the nation’s most treasured cultural and ecological sites – in order to expedite construction.Dozens of environmental and public health laws were brushed aside to build walls through parks and wildlife areas, including Organ Pipe Cactus National Monument, Cabeza Prieta National Wildlife Refuge, San Bernardino National Wildlife Refuge and Coronado National Memorial. “It has brought devastation to the environment and the communities of the borderlands,” says Scott Nicol, author of a 2018 report for the American Civil Liberties Union (ACLU) about the impact of the wall, and a resident of the Rio Grande valley in Texas.Nicol believes the wall’s charted course has been determined by ease rather than efficacy. Construction has been much busier on federally owned land, not because that’s where there are likely to be more border crossings, but because building on private property is a lengthy process. “Texas has the most border but the least wall mileage to date because the Texas borderlands are mostly in private hands,” says Nicol.According to the US Customs and Border Protection (CBP) agency, 452 miles of border wall have been constructed under the Trump administration, at an estimated cost of $15bn, one of the most expensive infrastructure projects in US history. In September 2019, Trump promised to build between 450 and 500 miles of wall, so he has reached this goal – even if the vast majority of it is replacing existing barriers.On Tuesday, days after the violent insurrection at the White House, Trump made a final visit to the border in Texas to celebrate reaching this target. During a short speech, he skirted any responsibility for the capital siege, and instead remarked on his successes in halting illegal immigration and securing the border.“When I took office, we inherited a broken, dysfunctional and open border,” he said. “We reformed our immigration system and achieved the most secure southern border in US history.”Has it had any impact on immigration? According to attorney David Donatti, from the ACLU of Texas, the answer is no. In recent months, according to CBP data, the number of people trying to cross has increased. “The wall as a whole is unlikely to have any discernible impact,” says Donatti. “In a race to construct, the administration is building where it’s easier as opposed to where most people cross.”And while the wall may be an impressive barrier, it is far from impregnable. Just after Christmas, Nicol visited a new section in the Rio Grande valley between Texas and Mexico and found numerous ladders scattered on the ground. “You can always go over,” he says.You can also go through. John Kurc started using drones to photograph and video the construction of the wall. The last time he was in the border town of Sonoyta, Mexico, he saw two young men with “yellow, handheld angle grinders” cutting through the wall while a lookout with a radio watched for Border Patrol. “They would put the section back with a special bonding agent and then use paint that oxidizes the same colour as the bollards,” says Kurc. “Then they just go in and out.”Gil Kerlikowske, the Obama-appointed former commissioner of the CBP, says there is not a one-size-fits-all solution for border security: “There are places where the environment is difficult and so remote you don’t need any barrier at all.” In these areas, surveillance and detection technologies would be more useful and cost-efficient, he argues. “It is such an unbelievably complex problem. When someone proposes a simple solution to a complex problem, you can be sure that’s the wrong solution.”***That’s not to say Trump’s wall has had no impact. Back on the ranch, cameras set up by Melissa Owen have captured passing wildlife – mountain lions and javelina, pig-like mammals, the skulls of which can also be found around the house. “There were no environmental surveys, no groundwater surveys, none of that,” says Owen. Once contractors arrived in town last summer, they began “pumping enormous amounts of water out of the ground” in order to mix concrete for the border wall’s foundations.Residents in Sasabe began complaining of reduced water pressure. At San Bernardino National Wildlife Refuge, groundwater pumping for concrete began draining a crucial wetland and endangering four threatened species of fish. Similar concerns were raised when the Quitobaquito Springs at Organ Pipe Cactus National Monument, home to the endangered desert pupfish began to dry out as contractors pumped water from the ancient aquifer that fed it. “That’s our water – that’s what we depend on,” says Owen, looking out towards arid ranchland that is suffering from a long drought.We had three different jaguars in 2016 – we haven’t seen signs of any since construction beganMyles Traphagen, borderlands coordinator of the Wildlands Network conservation group, has called Trump’s wall the “single most damaging project” to the ecology of the mountainous Sky Islands region and the animals that call it home – especially the jaguar, which has made a remarkable comeback in the US after being hunted to extinction by the late 1960s.“We had three different jaguars in 2015 and 2016, which hadn’t happened since the 1930s,” says Chris Bugbee, a senior researcher at Conservation CATalyst, an organisation dedicated to the world’s 38 wild cat species.“If this border wall hadn’t started, we expected a female to eventually arrive and have breeding jaguars again,” adds Aletris Neils, Conservation CATalyst’s executive director.The jaguar is one of numerous species – such as the endangered ocelot and the Mexican gray wolf – found in a region that extends from south-western New Mexico into western Arizona and far down into Mexico. If current border wall construction is completed, says Traphagen, “93% of jaguar habitat will have been walled off”.Only males have been seen in the US since the 60s. They have huge ranges and some travel north where there is plenty to eat, before returning south to find a mate. There is currently one jaguar (whose location cannot be shared due to poaching concerns) on the US side, cut off from Mexico because of the wall.Bugbee has spent years tracking the famous “El Jefe” jaguar, one of the few sighted recently in the US, with his dog Mayke. “We haven’t seen signs of any jaguars since construction began,” he tells me when we meet at the Coronado National Forest, where he previously tracked the cat. A mile or so away, construction workers have been blasting and bulldozing over the steep Montezuma Pass, where another jaguar, known as Yo’oko, once roamed.Owen and McDaniel are far from open-border liberals. The entrance to their ranch has a sign that reads: “Border Patrol always welcome”. Owen’s two horses, Rocker and Kiowa, are retired Border Patrol horses – “the best”, she says of their temperament. In her early years on the ranch, Owen says, undocumented migrants and smugglers were coming across the border in large numbers. She would frequently encounter migrants on her property. One morning someone broke into her house. “I don’t want it to go back to then,” she says, but adds that the economic downturn of 2008 has slowed immigration considerably. “No one wants a secure border more than I,” she says. “But a 30ft-tall, poorly constructed barrier is not the answer. It’s a campaign gimmick. My neighbourhood is being destroyed because a megalomaniac wants to pacify his supporters.”During his election campaign, Trump claimed that Mexico would pay for the wall. Once he was in office, Congress provided some $1.37bn a year for construction, but each year the president demanded more, ultimately declaring a national emergency in order to divert military funds to pay for the wall. It’s estimated by the US Army Corps of Engineers that Biden will save about $2.6bn if he stops construction on the border wall in his first day in office.Trump, and some within CBP, have maintained that the wall is a crucial means of halting smuggling. “Illegal drug and human smuggling activities have decreased in those areas where barriers are deployed. Illegal cross-border traffic has also shifted to areas with inferior legacy barriers or no barriers at all,” said a DHS spokesperson in a recent email to the Guardian.Kerlikowske, who also served as director of the Office of National Drug Control Policy between 2009 and 2014, admits that drug trafficking is a problem. However, he points out that the vast majority of illicit substances, such as fentanyl, cocaine and heroin, are smuggled through legal ports of entry where elaborate walls and security systems already exist. “During my time as commissioner, I met with hundreds of border patrol agents. No one in the border patrol says we really need a wall,” he says.As you keep building, you keep pushing people into more remote and dangerous areasDonatti from the ACLU of Texas says there is little evidence that walls deter either drugs or undocumented immigration, which is being driven primarily by so-called push factors (war, poverty, desperation) in other countries. “The US federal government has tried to study this several times and has never found support that a border wall stops the flow of undocumented immigration,” he says.One thing border walls are effective at is increasing the number of migrant deaths. As the US has walled off more of its border, the risk to migrants crossing illegally has increased. Since 1998, around 7,000 people have died along the US-Mexico border, the majority in Arizona’s rural deserts and, in recent years, the Rio Grande valley. “As you keep building, you keep pushing people into more remote and dangerous areas,” says Donatti.“It’s a humanitarian disaster,” agrees Eddie Canales, of the South Texas Human Rights Center, who has spent the past decade operating hundreds of water stations in the Rio Grande valley in Texas to save migrants. “We do what we can,” Canales told the Guardian in early 2020. “But people keep dying.” The wall funnels people into more dangerous crossing points, where physical barriers do not yet exist. Summer temperatures in the Arizona desert are brutal; 2020 became the deadliest year since 2010 for those who crossed the border there.***“It’s hard for people to understand what this means to us, as O’odham and Native Americans. What it means to us as the original indigenous peoples of this land,” says Verlon Jose.When I visit Organ Pipe Cactus National Monument, a pristine tract of Sonoran desert, earlier this year, contractors are busy dynamiting Monument Hill, a sacred mountain and burial site for the Tohono O’odham people. Uprooted saguaros, the huge, tree-like cacti sacred to the tribe, dot the path of the wall. “It was like, ‘Tell me where your grandparents live, and I’ll put a wall through there,’” says Jose.“In certain areas, we won’t be able to continue our traditional practices,” says Jose, whose tribal members span both sides of the border. “We spent billions of dollars on the wall. Why don’t we invest it in our border cities and towns?”According to Norma Herrera, a border resident from McAllen, Texas, the wall’s $15bn price tag is an insult to one of the county’s most impoverished regions, where critical infrastructure is often lacking. This issue was laid bare during the pandemic, when places such as the Rio Grande valley in Texas, a centre of border wall construction, was devastated by Covid. Hospitals reached capacity, deaths mounted, and all the while, the wall continued to rise.“We had more deaths in the region than the entire state,” says Herrera, community organiser at the Rio Grande Valley Equal Voice Network, which advocates for marginalised groups in the area. “To see the wall going up, to see resources used on useless steel and concrete, it’s senseless.”According to Donatti, whose parents originally emigrated from Argentina to the US, the wall should be seen in the context of broader exclusion policies – such as the Remain in Mexico programme enacted by Trump, under which asylum seekers arriving at ports of entry are returned to Mexico to wait for their US immigration proceedings. “It’s this idea that there is a fundamental Americanness, and either you’re inside, or you’re out,” he says.That idea was evident in late 2019, when I visited a shelter in Tijuana. The two-storey building in the neighbourhood of Benito Juárez was packed with families, with mattresses sprawled over every inch of open floor. At that time in Tijuana, nearly 10,000 asylum seekers were waiting for their immigration hearings after being turned back at the border and sent to one of the most dangerous cities in Mexico.Many are hopeful that under the Biden administration the approach to migrants and the borderlands will change; that policies such as Remain in Mexico will be undone; and even that sections of the border wall will be removed. A week after inauguration day, a coalition of groups across the borderlands will begin a monitoring project in order to assess the damage, and to see what needs to be done. Some hope certain sections can be removed in order to reconnect critical habitats and communities.Verlon Jose of the Tohono O’odham has a “sliver of hope” that some of the walls will come down. “I believe Biden will not build another inch,” he adds.Others are not so sure. “Optimism? No,” says Donatti of the prospect of the wall coming down. “He hasn’t committed to as much. But there is a strong coalition along the border that will be fighting for it.”John Kurc, who has spent thousands of hours watching the destruction of Guadalupe Canyon, sees the scale of the challenge. “The Trump administration has caused so much damage to these environments,” he says, peering through a set of binoculars as a crane hoists up an isolated section of wall, with huge gaps on each side. “We have a lot of work to do.” More