The Drug Abuse Office and Treatment Act of 1972 placed primary responsibility for reducing domestic marijuana cultivation with State and local authorities and designated the Federal Government's role as one of leadership, coordination, and support. In responding to a GAO questionnaire, the State law enforcement agencies participating in DEA's 1983 program reported that the major impact of their enforcement efforts was that growers changed their cultivation methods. Many growers are moving their operations indoors or taking other measures to better hide their crops grown outdoors. Most States reported that they expect domestic production to continue to increase during 1984 and 1985. Various resources were indicated as needed by the States, including data on domestic marijuana trafficking, helicopters, and off-road vehicles. The National Guard and the Department of Defense (DOD) may be able to help meet some of these needs, particularly air support to help locate and destroy marijuana grown outdoors. Under its Domestic Marijuana Eradication/Suppression Program, DEA is responsible for the coordination of assistance of other Federal agencies.