Zappia's work lies at the intersection of the public and academia. For more than two decades, he has engaged in numerous public history projects involving collaborations with museums, non-profit organizations, and high schools. Organizations include the Institute of American Indian Art, Los Angeles County Natural History Museum, Academy of Motion Picture Arts and Sciences, Leslie Marrowbone Lakota Sioux Youth Program, NEH Teaching History Initiative, UCLA Center X, Autry National Center, and UCLA Public History Initiative. His first book (co-authored in 2006 with Steadman Upham), The Many Faces of Edward Sheriff Curtis: Stories and Portraits from Native North America, served as a public history collaboration between Claremont Graduate University, the Gilcrease Museum, and the Los Angeles County Natural History Museum, where Zappia cataloged the unpublished field notes of Edward S. Curtis and lectured at the opening exhibit.
More recently, Zappia has turned his attention to local Los Angeles-based outreach efforts, including the “Play the LA River” (P-51) project (www.playthelariver.com). P-51 was a yearlong multidisciplinary humanities initiative connecting communities throughout Los Angeles to the region’s 51-mile concrete river. Between 2013-15, Zappia served as the programming and outreach coordinator for the project.
Zappia continues to consult on projects with the Autry National Center, KCET, UCLA, and LAUSD. In 2016-17, he was a visiting scholar at the Institute of American Cultures at UCLA, where he co-coordinated an "Indigenous Foodways" public lecture at the American Indian Studies Center and Mildred E. Mathias Botanical Garden. In 2018, he was named co-director of the Integrated Arts and Humanities Program at Whittier College. Funded by the Mellon Foundation, this initiative involves a national collaboration with Connecticut College to create new programs, curricula, and collaborations that strengthen the core mission of the humanities.