 During World War II, she earned her pilot’s license to qualify for the Women Air Force Service Pilots.Yeaman later earned a degree in Environmental Studies at the University of California at Irvine.In her early career, Yeaman worked as a Public Education Consultant and Water Conservation Coordinator at the U.S. Environmental Protection Agency in Washington, D.C.

She moved to the Upper Delaware River region in the early 1980s and became involved with the Citizens Advisory Council that helped to establish the Upper Delaware Scenic and Recreational River under the auspices of the National Park Service.