A border wall was a signature part of Donald Trump presidential campaign.
The president was never very specific. He just described it as big and beautiful.
That's his vision – and then there’s the reality. And in reality, building any kind of wall along the entire length of the U.S.-Mexico border is incredibly difficult.
"If you've never visited the border, if you live away from somewhere in the interior of the United States, it's really hard to visualize what it's like," says Daniel Gonzalez, a reporter at the Arizona Republic.
Gonzalez contributed to a documentary project from the USA TODAY Network called "The Wall," which examined the U.S.-Mexico border.
For the project, several journalists recorded their journey over the entire 2,000 mile length of it, both by car and by helicopter.
"When you see some of that footage," he says, "you can see there are areas where miles and miles and miles, as far as you can see, is nothing but desolate desert and rugged mountains."
These remote areas would be incredibly hard to develop, much less build a wall. But they're also not easy to travel over afoot, either.
Gonzalez saw this first-hand when he reported on an area in Organ Pipe Cactus Monument, located near Mexico's border with Arizona.
For people crossing the border on foot, it's incredibly dangerous. Those who are sick or hurt are often abandoned by the smugglers leading them across, without water.
In his reporting, Gonzalez found that this wasn't an isolated occurrence.
"As the border has become more fortified, it drives migrants to use more and more remote, treacherous areas of the desert to enter the country illegally," he says, "and as a result, more people are dying."
That's despite the number of people crossing illegally is at historically low levels.
"What that suggests is that the death rate, the chances of dying, are actually increasing," says Gonzalez.