Luna B. Leopold was a professor emeritus of geology and landscape architecture at UC Berkeley and the former chief hydrologist of the U.S. Geological Survey's Water Resource Division (USGS). Leopold was the son of Aldo Leopold, a pioneer in scientific wildlife management and author of A Sand County Almanac. Leopold spent some of his childhood in New Mexico which influenced his later interest in the lands and rivers of the Southwest area. He graduated from the University of Wisconsin with a degree in civil engineering, a master's degree in physics and meteorology from UCLA and a Ph.D. in geology from Harvard (1950). After Wisconsin, he worked with the Soil Conservation Service, Army Corps of Engineers, Bureau of Reclamation and the Pineapple Research Institute throughout the 1930s and 40s before settling at the USGS Water Resources Division as a hydrologist and research scientist. Here he worked on administrative reorganization, personnel policies, publications, new programs of scientific research field trips and managed relationships with other government agencies. He also published several scientific papers in hydrology, and geomorphology. Leopold was actively involved in many environmental issues such as the Florida Everglades Jetport, Trans-Alaska oil pipeline, the Colorado River, and Hell's Canyon. After leaving the Water Resources Division, Leopold held a position on the Sierra Club Board of Directors from 1968 to 1971 and moved on to teach at the UC Berkeley departments of geology and landscape architecture. In this interview, Leopold discusses his family and youth in Albuquerque, NM, and Madison, WI, the development of scientific skills and land ethic, father's influence, siblings Starker, Nina, Carl, and Estella, his education at Wisconsin, UCLA and Harvard, various jobs during his early employment, work at the USGS Water Resources Division and his thoughts on hydrology over the last fifty years. This history also contains an appended interview of USGS colleague David R. Dawdy.