The American Planning Association (APA) is a non-profit professional research organization committed to urban, suburban, regional, and rural planning. APA is the result of a merger between the American Institute of Planners (AIP), founded in 1917 and the American Society of Planning Officials (APSO), established in 1934. The organization has 46 chapters which generally correspond to state boundaries and is further subdivided into regional sections. This section is one of eight in California and covers Riverside and San Bernardino Counties. San Bernardino is the largest county in California and Riverside is one of the fastest growing counties in the state. The Inland Empire Section (IES) of the American Planning Association has over 500 members, representing the public, private, and academic sectors.