Illicit drugs continue to pose a direct threat to the United States with estimates in 2002 of 35.1 million persons aged 12 and older reported using an illicit drug in the last year. In addition, major drug trafficking organizations in Mexico and Colombia, as well as street gangs in the United States, pose a continuing threat to the United States national security. This national assessment report covering six regional areas provides information on the current threat and trends of illicit drugs in the United States for 2004 which entails specific information on the primary drugs of cocaine and crack, heroin, marijuana, MDMA, and methamphetamine, and pharmaceuticals and other dangerous drugs, as well as drug trafficking gangs and organizations and drug borders, points-of-entry, and corridors. Report highlights include: (1) Mexico and Colombia are the primary wholesalers of most illicit drugs in the United States and street gangs, outlaw motorcycle gangs, and prison gangs are the primary retailers; (2) cocaine and methamphetamine are the primary drugs behind a significant amount of drug-related violence; (3) overall, the demand for heroin is trending downward; (4) domestic methamphetamine production has increased; (5) pharmaceutical diversion and abuse are on the increase; (6) there are 14 primary market areas identified serving as major centers of consumption and distribution of cocaine; (7) most illicit drugs and money in the United States are transported on highways and interstates; and (8) synthetic drugs are becoming an escalating threat.