Tucson's Customs and Border Protection Air Operations Branch runs the largest air support group in the United States. Pilots patrol 365 miles along the U.S.-Mexico border.
KGUN spent the day with Customs and Border Protection Agent in an A-Star helicopter looking for drug smugglers and human trafficking.
"It's mostly marijuana because the smaller volume higher value drugs are more easily moved in compartments in cars and stuff like that," said CBP agent Johnson.
About 90 miles west of Tucson, an area patrolled by the Ajo station, is some of the most highly trafficked areas for marijuana smuggling.
"We can't quantify how much is moving because we can't see everything all the time," said Agent Johnson.
Human smuggling is also big business, and nearly all of this trafficking happens under the watchful eye of the cartel.
"The cartel controls everything," Johnson said. "There used to be a time a few years ago where people were pretty much crossing at will, some without camouflage."
Johnson said that is not happening much anymore. Now, ranches and barns serve as staging grounds for people to meet their cartel employed escorts.
"They carry backpacks that have clothes they can change into so they don't look like they're coming out of the desert smuggling in."
Then, the trek over mountains, through washes and across scorching desert begins. Stopping that movement is a tough fight against an invisible enemy for CBP agents.
"They're gonna hear you coming, and they're gonna stop moving, and they're gonna hug up on the base of a tree or go undercover, and they'll literally disappear," said Johnson of the experienced smugglers crossing through Southern Arizona's desert.
Between camouflage, carpet covered booties, and even scuba gear used to get through washes, Johnson said smugglers get creative to go undetected.
Agent Johnson said limited time and resources make it tough to find many groups of smugglers, and some of these operations are just distractions for bigger drug smuggling happening somewhere else:
"You're looking over here, and they're moving bigger and greater things somewhere else," said Johnson.
Regardless, that will not stop agents from tracking down every footprint they can trace if it means one less pound of drugs entering the United States.