Gwaltney began a long and illustrious career with the National Parks Service in 1977. While there, he held numerous positions, including as a Park Interpreter and Ranger, a Museum Curator and Technician, an Interpretive Designer and Trainer, the Chief Naturalist, a Diversity Educator, an Emergency Medical Technician, and most recently as the Assistant Regional Director, among other roles. He also worked at the National Museum of African American History and Culture and, from 2013 to 2016, at the American Battle Monuments Commission as Director of Interpretive and Visitor Services in Paris, France. After almost 40 years in public service, Gwaltney retired in 2016. He lives in Colorado and makes Fur Trade-era long riffles.