The US-Mexico border spans 1,933 miles. It runs from the Pacific Ocean to the Gulf of Mexico, across California, Arizona, New Mexico and Texas. President Trump's pledge to build a wall along the border was a key part of his campaign. He said this month that early construction of the wall would be funded with US tax dollars in order to get started quickly, and promised that Mexico "will reimburse us." Click through this gallery to see scenes from the border and perspectives from those who live and work near it.
Pamela Taylor, 88, has lived in Brownsville, Texas, since 1947. Taylor says she has had people from "all over the world" arrive on her property, and she says she has even found them in her living room. Every night, she fills a cooler in front of her house with bottles of water for migrants who made the journey, Border Patrol officers, or anybody else who finds themselves near the front steps of her house.
Taylor put this sign up down the road from her house during the 2016 presidential election. She says that the fence the US government put up near her property in 2007 doesn't work. "I would like for Mr. Trump, I would even feed him, if he will come down here and talk to the people," Taylor told CNN. "He is doing exactly what the government did to us in the beginning. He's not asking how it's going to affect the people that live here."
The Rio Grande forms a border between Texas and Mexico. Much of the river straddles remote desert and farmland, such as this stretch in Progreso Lakes, Texas.
On October, 26, 2006, President George W. Bush signed the Secure Fence Act, and said, "This bill I'm about to sign is an important step in our nation's efforts to secure our border and reform our immigration system." More than 1,250 miles of the border are in Texas, but the state only has about 100 miles of man-made borders. This fence line in Progreso Lakes, Texas, comes to an end, and leaves miles of border land open.
Greg Henington, owner of Far Flung Outdoor Center in Terlingua, Texas, says he doesn't believe a wall is necessary. "The wall is not going to make a difference one way or another. It's just going to cost a ton of money and look dumb."
In 1935, the federal government passed legislation that would enable the state of Texas to acquire the land that would become Big Bend National Park. The park, known for its remote beauty, shares the border with Mexico for 118 miles and is separated by the Rio Grande.
Lilia Falcon owns Jose Falcon's restaurant in Boquillas del Carmen, Mexico, across the Rio Grande from Big Bend National Park in Texas. The border crossing closed after September 11, 2001, and reopened in April 2013. "This town just went dead," Falcon told CNN. "We are very happy that the border is reopened again. We feel very safe here, even tourists that come over here, the word is spreading out more that its very safe to come here."
Many Texas residents in the Big Bend National Park region believe that the various miles of remote canyons and rivers already act as an "effective barrier" with Mexico.
Robert Cameron, owner of Texas Border Tours in Progreso Lakes, Texas, is in favor of President Trump's proposed wall, but he knows it will be complicated to build through parts with rough terrain. "I want to see a wall," Cameron told CNN. "Not a fence. I want to see a wall. I want to see something that you can't see through, that you can't climb through."
The scenic mountains, canyons and desert that make up the Big Bend region on the west Texas-Mexico border span an elevation of less than 1,800 feet near the Rio Grande to almost 8,000 feet in the Chisos Mountains.
Michael Ryan has worked as a ranger at Big Bend National Park since 1999, and 10 years as a river guide in the region previously. "It's not just one border, it changes depending on where you are," he told CNN.
The Boquillas Crossing, a one-of-a kind port of entry where you can take a small ferry boat across the Rio Grande and into the tiny Mexican village, reopened on April 10, 2013, following federal closure for more than a decade after the September 11, 2001, attacks.
Marcos Paredes has lived near Terlingua, Texas -- a former "ghost town" -- for much of his life. He spent years as a law enforcement officer responsible for patrolling the Rio Grande. "To come up with a one-sized fits all solution for illegal immigration is crazy," Paredes told CNN. "Because the border is so different along its entire links."
Alicia Bon Martin, born in Nogales, Mexico, and her husband, Chris Martin, work and live on both sides of the Arizona-Mexico border. They own organic farms in Mexico, a produce distributorship, and the restaurant La Roca, a Nogales, Sonora, institution started by Alicia's uncle and celebrating its 45th year anniversary this year. "We are lucky because we have the good things of both sides," Alicia told CNN. "I see this border as a much calmer than anybody portrays it to be."
Tim Foley founded The Arizona Border Recon in 2011, a nongovernment organization which provides intelligence to the US Customs and Border Protection. Foley has set up about a dozen cameras in the Sasabe, Arizona, desert and shares a database of smuggling activity that he says he captures with the Border Patrol. "It's a huge game of hide and seek," Foley told CNN. "A wall might help a little bit. But we have a wall here, or a fence, or whatever you want to call it. And it's not a deterrent -- it just slows them down for 10 seconds. So unless you have people watching the wall, it's not going to do anything. You need boots on the ground."
There are about 700 miles of fence along the 1,933-mile international US-Mexico boundary. This stretch in Sasabe, Arizona, has a fence that was built in 2007. "I think a barrier, a physical barrier, is definitely necessary," Shawn Moran, vice president of The National Border Patrol Council, told CNN. "Putting up a fence, putting up a wall, has stopped the vehicle loads from coming across the border. It has been almost 100% effective in doing that."
The westernmost part of the U.S.-Mexico border overlooks the Pacific Ocean, inside California's Border Field State Park outside San Diego, and adjacent to a public beach in Tijuana, Mexico. This area is known as Friendship Park/El Parque de la Amistad, a historic meeting place where generations from both nations have gathered to visit with family and friends "across the line."
The Galvez tunnel was discovered by US authorities in 2009, approximately 20 yards north of the national boundary in Otay Mesa, California. The tunnel is about 6 feet high, 4 feet wide, and goes about 70 feet below Earth's surface. According to Homeland Security Investigations special agent Juan Munoz, their San Diego-based task force has discovered more than 29 of these sophisticated tunnels in the past decade.
A US Customs and Border Protection officer patrols the fence in Otay Mesa, California. Patched holes in the fence are a common sight along this section of the border next to Tijuana, Mexico.