Michael J. Yochim worked in Yellowstone National Park for over two decades, and for five years in Yosemite. A planner for the National Park Service, he researched the parks' histories and drafted management plans to resolve ongoing controversies. Drawing upon his experiences and his doctorate in geography from the University of Wisconsin-Madison, Yochim authored several articles and two books about NPS policy-making: Protecting Yellowstone (2013) and Yellowstone and the Snowmobile (2009). An avid hiker, he walked all 1,200 miles of Yellowstone's trails and most of those in Yosemite and several other national parks. He retired in 2014 and now lives in Missouri.