The curator of the Catalina Island Museum opened the door to a musty backroom a few weeks ago hoping to find material for an upcoming exhibit on the World War II era. Closing the door behind him, he trudged down a narrow aisle lined with storage boxes and bins filled with gray photocopies of old letters, civic records, celebrity kitsch — and dust.

"No luck," curator John Boraggina muttered.

But as he made his way to a back corner, he noticed another row of boxes. He carried the largest to a table, blew off the dust and lifted the lid.

Inside were leather-bound journals and yellowing photographs showing freshly unearthed skeletons lying on their backs or sides, or curled as if in sleep. Many were surrounded by grinding stones, pots and beadwork....