Evidence of drug trafficking litters the Arizona desert. Trails wind through the sand, water bottles, clothes - even vehicles are abandoned after they've served their purpose.
The gas cans in the bed of a white pickup indicate it was used to refuel other vehicles in the smuggler's arsenal.
The convoy of drugs seems never ending. "The D.E.A. in Arizona, at one point, if it was less than 500 pounds, they wouldn't prosecute," says Lt. Matthew Thomas with the Pinal County Sheriff's Office. "That's the amount of drugs we have coming through here."
Thomas says the terrain in this area makes it ideal for smuggling. The desert valley is surrounded by mountains, which serve as look-out points for cartel members. "It's a daily event, the more drugs the cartels can push through, the more money they make."Thomas says.
Money is the motivator. One bust netted the Pinal County Sheriff's Office 8,000 pounds of pot, worth about $4 million in Pinal County. The street value can triple by the time it reaches the Midwest.
"Just one branch of the Sinaloa Cartel has brought over 60,000 pounds of marijuana each and every month through our county," says Sheriff Paul Babeu. "And it's billions and billions of dollars of profit that these cartels make."
Babeu has run out of places to put all the drugs seized by his office. An area that was designed to process vehicles for evidence is now being used to store drugs. It's about six feet deep, four feet wide and 20 feet long. It's packed with bricks of marijuana. Two more storage units are also loaded with drugs, saved until the people who brought it over the border are prosecuted.
"We bring in so much we can't dispose of it, or incinerate it fast enough," says Elias Johnson, the Public Information Officer for Babeu's office. "It gets so heavy, the packs actually break up."
Most of the packages are marked with letters, numbers, words or pictures. The markings are not random. The codes are used by the drug cartels to determine where these drugs will go. That could be anywhere from California, Colorado, even Iowa. Art Vogel, the resident agent in charge of the Drug Enforcement Administration in Des Moines says the codes can also be used in reverse. "On occasion those markings, colors; etcetera indicate who the original packager or sender was. On the other hand, they can also indicate, once they're across the border, what groups in the U.S. they may be destined for."
The drugs seized in Iowa have similar markings to those seized in Arizona. "Those groups impact Iowa tremendously," says Vogel. "All of the drugs we see come into Iowa originate in Mexico and work their way across the border."
The drugs work their way up to the Midwest via the country's interstate system - from Interstates 8 and 10 in Arizona, to Interstates 35 and 80 in Iowa. "So just by the nature that I-35 and I-80 run through Iowa and intersect right here in Des Moines, that does have a bearing on how many drugs we see here in Iowa."
The vast majority of the drugs go undetected. The D.E.A. estimates it intercepts just 10 to 15 percent of the drugs traveling on the nation's interstates and highways. "You're talking about the heartland of America," says Babeu. "You look at your corridors and the trafficking that comes into Iowa and it can travel East and West through the main distribution points."
Stopping it, starts at the border. Those on the front lines say it's a war, a war getting bloodier by the day.