Lori Riddle (formerly Lori Thomas-Luna) is an Akimel O'odam Indian Tribe member who promotes environmental justice in Arizona.[1] Riddle is the co-founder and director of the Gila River Alliance for a Clean Environment (GRACE), a group focused on environmental health and justice issues on the Gila River Indian Reservation, and serves on the board of Greenaction for Health and Environmental Justice. [2][3] She is best known for her work regarding the Romic Environmental Technologies Corporation chemical treatment plant, the Stericycle medical waste incinerator and the Arizona Loop 202 freeway expansion.