The Northeast region of the United States includes Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and the District of Columbia. These findings are derived through detailed analysis of the most recently available reporting from law enforcement, intelligence, and public health agencies. Distribution and abuse of heroin are widespread and increasing significantly, particularly in suburban and rural communities. Treatment data indicate that heroin-related admissions to publicly funded facilities increased by more than 28,000 between 1999 and 2001. High-purity South American heroin is the most prevalent type available. Southeast and Southwest Asian heroin and, to a much lesser extent, Mexican black tar heroin and brown powdered heroin also are available. New York City serves as a primary market area for heroin in the Northeast. Boston, Baltimore, Newark, Philadelphia, and Washington, DC also play prominent roles in regional heroin distribution. Colombian and Dominican drug trafficking organizations and criminal groups control most of the wholesale-level distribution of South American heroin in the Northeast. Asian and Nigerian criminal groups are the primary wholesale-level distributors of Southeast and Southwest Asian heroin. Dominican criminal groups are the primary retail distributors throughout the Northeast but numerous other retail heroin distributors are also active.