Zepeda has worked with her tribe to improve literacy in both English and Tohono O'odham. In 1983 she developed A Papago Grammar from tapes of Native speakers because no textbook existed for the classes she taught. Her work with the reservation committee for Tohono O'odham language policy yielded an official policy that encourages the speaking of the Native language at all grade levels.
In 1999, Zepeda received a MacArthur Fellowship. She is the Poet Laureate of Tucson, Arizona. For several years, she continues to serve as editor for numerous journals and book series. In 2012, her book was banned by Tucson schools.