The next morning, as a fog bank lingers offshore, Gill takes me to an even more improbable village site on the north side of the island while Erlandson goes prospecting for new sites and interesting geology. It’s a grueling hike up and across the side of Mount Diablo and then down old sheep paths to a site Gill calls Diablo Valdez, which provided much of the data for her PhD dissertation. Aside from a few rare copses of live oaks, there’s no shade en route, and the ocean glitters far below the rocky slopes. We arrive sweat soaked, and a film of dust covers the tattooed hummingbird on Gill’s arm.