In 1972, the U.S. based Texaco Corporation began oil production in the upper Amazon, operating for 20 years without any environmental regulations or public health guidelines. The result was the largest and most sustained oil disaster to date, for which damages are now being sought in a class-action lawsuit by the Ecuadorian people. This project examines how damages to health and the environment from oil development in the Ecuadorian Amazon are accounted for and translated into forms of evidence in order to be mobilized and acted upon in scientific, legal, and social arenas. The translation of damages into evidence by lawyers, scientists, advocates, and residents is significant because it is a means for making claims to truth, action, and reality. Over a twelve-month period, I will conduct community-based ethnographic research and document collection in order to investigate how the practices of measurement, documentation, and narration construct the reality of oil damages. This project contributes to anthropological scholarship on disaster and response, and draws on science and technology studies to examine the production of evidence and documentation practices of oil damages. By examining how evidence of oil damages is produced and mobilized in a multi-national case in the Amazon, this project also contributes to public and interdisciplinary academic knowledge about the human and environmental costs of oil development worldwide.