The Government Accountability Office's report revealed that from fiscal years 2011 through 2016, 67 cross-border smuggling tunnels were discovered along the U.S.-Mexico border. Sixty-two out of the 67 smuggling tunnels were in the Border Patrol’s Tucson, Arizona, and San Diego, California, sectors which are known strongholds of the Sinaloa Cartel.
The GAO also found there were 534 detected ultralight aircraft
incursions and 309 detected incidents of drug smuggling that involved
small fishing vessels. Seventy-five percent of the maritime drug
smuggling incidents occurred on the Pacific coast.
“While these methods account for a small proportion of known
smuggling, they can be used to transport significant quantities of drugs
or for terrorist activity,” the report noted.