As the world’s largest professional organization devoted to the study of mammals, the American Society of Mammalogists considers science the cornerstone for all studies of the natural world. As stated in our letter of 2 February 2017 to President Trump, we view science as the primary force driving advances in production, agriculture, and medicine, as well as knowledge of all aspects of nature. The unprecedented pace of discovery, the accelerating rate of data acquisition, and the ever-expanding range of phenomena under study demonstrate unequivocally the primacy of science for exploring the unknown. The American Society of Mammalogists urges continued public support of – and trust in – scientific inquiry and the use of science-based data as the foundation for decisions and policies affecting life on Earth.