Carole Lewis throws herself into her work as if something big is at stake. "Pa'-ah," she tells her Eureka High School class, gesturing at a bottle of water. She whips around and doodles a crooked little fish on the blackboard, hinting at the dip she's prepared with "ney-puy" – salmon, key to the diet of California's largest Native American tribe. For thousands of years before Western settlers arrived, the Yurok thrived in dozens of villages along the Klamath River. By the 1990s, however, academics had predicted their language soon would be extinct. As elders passed away, the number of native speakers dropped to six. But tribal leaders would not let the language die. Last fall, Eureka High became the fifth and largest school in Northern California to launch a Yurok-language program, marking the latest victory in a Native American language revitalization program widely lauded as the most successful in the state...