TOHONO O'ODHAM NATION, AZ - JANUARY 18: Suspected drug smugglers' footprints mark the sand on January 18, 2011 in the Tohono O'odham Nation, Arizona. The prints were being tracked by officers from ... more 
TOHONO O'ODHAM NATION, AZ - JANUARY 18: Suspected drug smugglers' footprints mark the sand on January 18, 2011 in the Tohono O'odham Nation, Arizona. The prints were being tracked by officers from the Shadow Wolves, the only Native American unit of the U.S. Immigration and Customs Enforcement agency. The ICE unit tracks and interdicts drug smugglers and illegal immigrants crossing into the Indian reservation along a 72-mile stretch of the U.S.-Mexico border. The reservation is a key crossing point for narcotics entering the United States. (Photo by John Moore/Getty Images) less 
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Getty Images | Photo By John Moore / Getty Images
Wed, Jan 19, 2011 11:08 AM EST