Southern California Association of Governments

The Southern California Association of Governments (SCAG) is the metropolitan planning organization (MPO) of six of the ten counties in Southern California, serving Imperial County, Los Angeles County, Orange County, Riverside County, San Bernardino County, and Ventura County. San Diego County's MPO is the San Diego Association of Governments, which is an unrelated agency. SCAG is the largest MPO in the United States, representing over 18.5 million people in an area covering over 38,000 square miles (98,000 km2). As the designated MPO, SCAG is mandated by the federal government to research and draw up plans for transportation, growth management, hazardous waste management, and air quality. Additional mandates exist at the state level