Don Christensen has spent 35 years in public education in Orange County, California, at the high school, community college, and university levels teaching history, political science, anthropology, and coaching men and women's cross country and track and field before retiring. He has 37 years of experience doing archaeological survey, excavation, and rock art recording for a number of cultural resource management companies in California and for the Bureau of Land Management, the United States Forest Service, and the National Park Service in Arizona, California, Nevada, and Utah. Specifically he has 22 years of experience working on projects for the Grand Canyon National Park, Grand Canyon-Parashant National Monument, Grand Staircase-Escalante National Monument, BLM/Arizona Strip, and the Kaibab National Forest. He has published numerous articles in journals and authored technical reports for federal resource agencies.