Remaking California’s Central Valley wetlands was a complicated project that took much of the 20th century. Resurrected from degraded farmland and cash-strapped gun clubs, assembled by bulldozer and backhoe, the current patchwork of national wildlife refuges, state wildlife areas, and county preserves is much diminished from the four million acres of primeval wetlands that spanned the Central Valley before it was farmed. Nevertheless, these habitats are ecologically significant on a hemispheric level, serving 60 percent of migratory waterfowl on the Pacific Flyway, including three million ducks, two million geese, and a half million shorebirds. Their restoration has lured hungry birds away from agricultural fields, created wilderness access for rural communities, and returned endangered species to viable numbers. Decades before the spread of concepts like the Anthropocene and reconciliation ecology, refuge managers were devising ways to sustain ecological systems that had been dramatically altered.