Trump orders construction to begin on border wall

A 3.6-mile stretch of the U.S.-Mexico border fence, completed in 2009, cost $57.7 million to build through rugged terrain east of San Ysidro. A wall along the entire border could cost between $12 billion and $38 billion.  (Don Bartletti / Los Angeles Times)

Sunset on the U.S.-Mexico border in Naco, Ariz.

A Border Patrol agent along the “floating fence” that sits atop the Imperial Sand Dunes in southeastern California.  (Don Bartletti / Los Angeles Times)

The U.S.-Mexico border fence at Border Field State Park in San Diego.

An opening in the border fence near McAllen, Texas.

The border fence separating the towns of Anapra, Mexico, and Sunland Park, N.M.

With a rifle slung over his shoulder, Bob Maupin gazes toward Mexico over a fortified fence he built along the border to discourage immigrants from trampling over his property about 65 miles east of San Diego.

Border Patrol Agent Eduardo Olmos near the secondary fence separating Tijuana and San Diego.

The fence stops near McAllen, Texas.

The border fence at the base of Otay Mountain in San Diego County.

The fence a few miles east of Campo, Calif.

Near San Luis, Ariz.

A U.S. Border Patrol agent gazes across the border fence in San Diego County.