Sarah Thomason is also known for her contributions to the study of Native American languages. Thomason's interest in these languages started with her studies on pidgin languages, specifically pidgin Delaware, derived from Delaware languages, and Chinook jargon. She would later become very interested on Salishan languages, a field that she has been studying for over thirty years. She has spent every summer since 1980 studying Montana Salish, or Salish-Pend d'Oreille language, talking with its last fluent speakers with the objective of documenting the language, as well as creating a dictionary for the Salish and Pend d'Oreille Culture Committee language program.