Robert McEwen began studying astrology at age 16 under an astrologer named Thane in Beverly Hills. He is a Mentor in a school of Ontology called The Prosperos and has been active with numerous academic, metaphysical, and astrological associations throughout his career. Much of his teaching has taken place in Southern California, Portland, and Seattle. He also organizes informal astrology meetup groups focused on Western natal astrology, sometimes conducted over Skype, continuing a practice he began doing in Portland in the 1970s.