Council Agendas Commission Agendas Calendar of Events Welcome to the City of Gustine! Gustine is a general law city and became incorporated November 11, 1915. Gustine was originally established as a Colony Center in 1895. Housed with a population of 4, 279 Gustine is located along the western side of Merced County in the San Joaquin Valley. The existing city boundaries of Gustine covers ...