"According to the DEA’s 2018 annual drug threat assessment, the vast majority of narcotics (including heroin, meth, and fentanyl) seized by Customs and Border Protection come through ports of entry either in packages, cargo, or with people who attempt to enter the US legally. The only drug that is smuggled in higher numbers between legal entry points is marijuana. When drugs are trafficked between points of entry, they are often moved through tunnels, not carried by migrants on foot. "