Donna L. Gillette Has a Ph.D. in Anthropology from University of California, Berkeley. Research interests include the study and documentation of PCNs, a very early rock art tradition that spans the Coastal Ranges of California. Other interests include working with an 1838 Rancho Period Adobe founded on a Native American site and interfacing with Native Americans. Mavis Greer Has a Ph.D. from University of Missouri, Columbia. She is co-owner of Greer Services, Archeological Consulting, Casper, Wyoming. Her interests include rock art and ethnohistory of the Northern Plains of North America, tipi ring analysis and cultural resource management. William Breen Murray Has a Ph.D. from McGill University in Montreal, Canada. From 1976 – 2006 he was a Professor in the Departamento de Ciencias Sociales, Universidad de Monterrey, Mexico. His research focus is archaeoastronomy, hunter-gatherer adaptation and numerical representation. Michele Hayward Has a Ph.D. from Pennsylvania State University and is currently a senior archaeologist with Panamerican Consultants, Inc. She has been involved with a variety of archaeological projects in the United States and the Caribbean. Her interest in Caribbean rock art began as an archaeologist at the Institute of Puerto Rican Culture and has grown to include documentation of rock art sites, as well as organizing and participating in national and international sessions on Caribbean rock art. She co-edited Rock Art of the Caribbean (2009).