AP PHOTOS: In Tijuana, faces of the US-Mexico border

In this April 5, 2017 photo, Californian Yesenia Huerta, 23, poses for a portrait in Tijuana, Mexico. Huerta, who says she is citizen of the universe, lives in Tijuana because it's more affordable than San Diego. She crosses to San Diego almost daily to study journalism and work part time in a sporting goods store. (AP Photo/Rodrigo Abd) (The Associated Press)

In this April 5, 2017 photo, Sinaloans Juan Lopez and wife Luz Noris, pose for a portrait in Tijuana, Mexico. The couple, who now live in Tijuana, cross the bridge to the United States only to go shopping and to visit relatives. They say it is much more difficult to get across now than in the past. (AP Photo/Rodrigo Abd) (The Associated Press)

In this April 5, 2017 photo, construction worker Paul Johnson, 31, from San Diego, poses for the portrait in Tijuana, Mexico. Johnson was returning to the U.S. after spending some time at the beach south of Tijuana. (AP Photo/Rodrigo Abd) (The Associated Press)

Over two weeks, AP journalists Rodrigo Abd and Christopher Sherman logged 3,000 miles in a rented Jeep traveling from the Gulf of Mexico to the Pacific Ocean, crisscrossing back and forth across the world's 10th-longest border 22 times and blogging about the experience .

All along the way they were looking for the right place for Abd to spend a day using his wooden box camera to make striking black-and-white portraits of the people who inhabit the frontier lands. It's a primitive device consisting of a box with a lens and space for a developing lab inside, and shooting, developing and digitizing the images is a painstaking process.

On the last full day of the trip, they finally set it up on a sidewalk in Tijuana, Mexico, near where people enter and leave the Chaparral border crossing. Most were coming or going in a hurry. But some, such as recent deportees from the United States, were just hanging around trying to figure out their next moves.

One by one they posed for the camera in front of a black backdrop and told the journalists a little about themselves, why they were there and what it's like to live along the border at a time of uncertainty for U.S.-Mexico relations under the presidency of Donald Trump.

Then Abd and Sherman used the box camera to take photos of each other, documenting the end of their journey.