Mary HillGeologist Mary Hill is the author of Gold: The California Story (California, 2002) and California Landscape: Origin and Evolution (California, 1984). She is coauthor of Volcanic Eruptions of 1980 at Mount St. Helens: The First100 Days (1982). Longtime editor of the magazine California Geology, she was later Western Region Information Officer for the U.S. Geological Survey and Adjunct Professor of Geosciences at San Francisco State University. Read More Read Less