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Aerial search for illegal border crossings along active Rio Grande

John Moore / Getty Images

A U.S. Border Patrol agent escorts a group of undocumented immigrants into custody with helicopter support from the U.S. Office of Air and Marine on May 20, near the U.S.-Mexico border in Havana, Texas. The Rio Grande Valley area has become the busiest sector for illegal immigration on the whole U.S.-Mexico border with more than a 50 percent increase in the last year.

John Moore / Getty Images

The Rio Grande snakes between Mexico and the United States, forming the international border on May 21, near Harlingen, Texas. The area is active for drug smugglers bringing their product north from Mexico into the United States.

John Moore / Getty Images

U.S. Border Patrol agent Ryan Bell looks for drug smugglers on the bank of the Rio Grande at the U.S.-Mexico border on May 21, near Hidalgo, Texas.

John Moore / Getty Images

Cars drive from Matomoros, Mexico, left, across the U.S.-Mexico border at the Rio Grande on May 21, into Brownsville, Texas. The area is active for legal international commerce as well as drug smugglers bringing their product north from Mexico into the United States.

John Moore / Getty Images

A U.S. Border Patrol agent searches for drug smugglers near the Rio Grande at the U.S.-Mexico border on May 21, near Hidalgo Texas.

John Moore / Getty Images

Mexican Army troops stand guard on the Mexican side of the Rio Grande at the U.S.-Mexico border on May 21, near McAllen, Texas.

John Moore / Getty Images

The Mexican border town of Matomoros is seen on the Rio Grande across the U.S.-Mexico border on May 21, near Brownsville, Texas.

John Moore / Getty Images

A suspected drug smuggling scout paddles his raft back across the Rio Grande into Mexico from the U.S. side of the border on May 21, near Hidalgo Texas.

John Moore / Getty Images

The mouth of the Rio Grande releases fresh water into the Gulf of Mexico forming the border between the United States. left,, and Mexico, right, on May 21 at Las Palomas Wetlife Management Area, Texas. The area, popular with tourists as well as wildlife, is also attractive to drug smugglers bringing their product north from Mexico into the United States.

NBC’s Mark Potter recently took an aerial tour of the Arizona portion of the U.S.-Mexico border. Click here to watch the report.

In 2011, Potter reported on dramatic aerial video showing law enforcement efforts to track drug smugglers from the air. Click here to see the video.

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