During the 1970s, after returning from the army, Forrester helped to set up the Central Australian Aboriginal Congress (CAAC), a health care service for indigenous people. He served as a field officer, and then later as its secretary. He also helped to set up the Central Land Council. In 1982, he represented Australia at the first session of the United Nations Working Group on Indigenous Populations, held in Geneva. In the middle of the 1980s, he helped to set up the Central Australian Aboriginal Media Association (CAAMA). He has served as the organisation's treasurer, manager, and as a board member of its television network, Imparja.