But the Chumash, whose ancestors helped shape the island’s ecology for more than 10 millennia, no longer live on Santa Cruz. The only people allowed on the western side of the island today are visiting scientists, students, and a small maintenance crew who roam what is a vast research park, with no paved roads, kilometers of empty beaches, and gorgeous views without a condo or hotel in sight. Erlandson and Gill let me tag along as they looked for ancient sites during a recent expedition.